OH, and one more small thing...........


Happy Thanksgiving

quote:

Originally posted by michael458:
OH, and one more small thing...........


Happy Thanksgiving

Back at you Michael!!!

quote:

Originally posted by michael458:
OH, and one more small thing...........


Happy Thanksgiving

..and you too!

Keith

Ok, hopefully I'm not going off topic here, but the 8208 Information gathered here brings me to this question... I'm wanting to ge back to using 500gr. Swift in my Lott that I went to Woodleigh's due to my AA2520load of 82grns. Was too compressed with Swift's. So I guess my basic question is, with 82.0grs. 8208 paired with Swift 500grn. Will this load be over compressed?? I'm currently doing 2210fps with mentioned load in my 21" barrel Lott.

quote:

Originally posted by MopaneMike:
Ok, hopefully I'm not going off topic here, but the 8208 Information gathered here brings me to this question... I'm wanting to ge back to using 500gr. Swift in my Lott that I went to Woodleigh's due to my AA2520load of 82grns. Was too compressed with Swift's. So I guess my basic question is, with 82.0grs. 8208 paired with Swift 500grn. Will this load be over compressed?? I'm currently doing 2210fps with mentioned load in my 21" barrel Lott.

Mike.........

Actually I think you have hit on a subject that should be discussed a bit, and that is
"Compression".....

I hear this concern all too much, and I think its time I try to explain some things concerning compression, and maybe we come to a better understanding of the term as we apply it to handloading. I hear concerns from experienced handloaders as much as novice handloaders, and its simply not understanding compression that leads to these questions......

So, lets get started on a few points this morning concerning this very important issue as it applies to us.

Compression is not a bad thing, and in most cases, we should strive for loads that are compressed, at least to a point. Most compressed loads tend to be the most consistent, both in velocity, and with pressure and pressure curves as well. They tend to burn the best in general terms.

Compression for us bolt gun guys gives us another advantage as well. If we have a properly compressed load, then our #3 or #4 cartridge down will have a difficult time seating itself deeper in the case, caused by recoil of the top 2-3 rounds. How many times have we heard that "Pressures Went Ballistic on my Last Round in the magazine because it became Compressed during Recoil"..... Have you heard that before? I trust most of us have.......

Now, in the above statement, I say compression is a good thing, but yet, because of a bullet being seated deeper in the case than normal, this caused compression, and raised pressures! How can this be? Can this actually happen? Yes... Let me explain.....

OK, lets take a relatively fast burning powder in the case of 458 Lott and 458 Winchester, RL 7. For 458 Lott and 458 Winchester we would consider RL 7 relatively fast in comparison with some other powders such as IMR 8208, AA 2230, and some others. If you notice, I use the slower burning powders mostly with the heavier bullets, 450 gr +, and our faster powders RL 7 and H-4198 for our lighter bullets in these cartridges, there is a reason for that. For example take IMR 8208 or AA 2230 and lighter bullets, it burns way too slow for us to get our velocity up, we can't get enough powder in the case to raise enough pressures with the lighter bullets to get optimum velocity with light for caliber bullets, so we have to go faster. Now, in reverse, if we take these faster powders, RL 7 and H-4198, to heavier bullets, then we reach max pressures too quickly with too little powder, and cannot reach optimum velocity.

If we look at RL 7 and H-4198 with the 450 gr #13 Solid with our 458 Winchester, we see that RL 7 reached 2270 fps with 62304 PSI, Max Pressure. As I recall, there is not much compression there, this load would need a heavy crimp to keep the bullet from moving deeper in the case during recoil. It is already at 62000 PSI, max pressure, if it seats deeper, then pressures are going to rise substantially, and for sure be an over pressure load. In some extreme cases this could lock the gun up pretty tight....... Not good in a DG situation. We also see that 60/IMR 4198 took us with the same bullet to only 2168 fps at 61033 PSI, not compressed, could be a bad problem with a bullet that is seated deeper.

Now, lets look at the same 450 #13 Solid and 77/AA 2230... This is pretty heavily compressed, it gives us 2311 fps at 59453 PSI. A decent crimp on this and it is not very likely for recoil to seat this bullet any deeper in the case, and even if it could slightly, we have at least 3000 PSI to reach max pressures. A decent gun won't lock up until it is a good way past Max. This load, being compressed is pretty much optimum, as would be several other loads we have listed, IMR 8208 among them.....

When I was loading 458 Lott and 458 Winchester I was using RL 15, and it was HEAVY COMPRESSED, so much so, that I had to be extremely careful as these loads were so heavy compressed they would actually BULGE the case sometimes, and therefore not even chamber in the rifle. So I had to be careful, and had to chamber every cartridge to make sure it worked in the gun. Pressures would run low 50000 PSI. I could not possibly get enough powder in the case to run pressures too high, even in 115 degree Zimbabwe heat. As we recently learned, RL 15 in 2013 is even slower than RL 15 of only 2 years ago. The same load in 458 Lott that I tested in 2011 came in 100 fps less and 45000 PSI. There is no way I can get enough RL 15 in the case today that would match some of our better loads with IMR 8208 and other powders........ Compression is only a problem here if we get so much we BULGE THE CASE....... You can't get enough in the case to case an issue or even come close to an issue in these two cartridges.

Weight Equal Pressure.... Weight is one of the factors that raises pressures, and the easiest to understand. So we see that with 450 gr bullets in 458 Winchester, our faster burners, RL 7 and H-4198, IMR 4108 builds pressures too fast, in most cases, less velocity than we desire, and higher pressures with little to no compression. But as we decrease weight, we see our slower powders are of little use to us, but RL 7, H-4198, and IMR 4198 come into their own in 458 Lott and 458 Winchester. As we drop to 400 grs we see better use of these powders, but from the 370#13 HP seated deep, 400 North Fork Softs, we see RL 10X and H-322 sitting nicely there, little slower than the RL 7/H-4198, but little faster than IMR 8208 and AA 2230, so these medium weight bullets work good with those. As we drop to the 250s to 350s we see RL 7, H-4198, and IMR 4198 being the only powders to get velocity up to where we would expect it. And again, some of these, most of these higher velocity loads are compressed, even with RL 7, H-4198..... And not a problem just because it is compressed.

Lets look at Case Capacity and powders just a bit as well. Two cases, 1. My own little 1.65 Super Shorts, which burn best with WW 296 and LilGun. Now, I have used RL 7 in these cases to good effect, but in these cases, like RL 15 in the 458 Winchester, I can't get enough powder in the case to run pressures up, nor can I get optimum velocity with RL 7 in these cases. RL 7 considered relatively fast in 458 Lott and 458 Win, would be considered SLOW in the Super Shorts.....

Now, along these same lines, lets look at the difference between the 450 #13 Solid and the 450 North Fork FPS Solid..... In particular the case of 458 Winchester, which is all fresh in my memory since working with that the last few days. In almost every case, if I was at top end pressures with the 450 #13 Solid, then I had to drop a grain or two when going to the 450 North Fork. Why? Because of where I seat the North Forks is slightly deeper than the 450 #13. Look at IMR 8208 with the two bullets. 450 #13 76/IMR 8208 2322 fps at 61000-62000 PSI, basically Max Pressure. With the 450 North Fork I dropped to 74/IMR 8208 2270 fps and 60000 PSI. Now I might could have gone to 75/IMR 8208, but I am quite sure I would be all over 62000 PSI +, so I did not. I Might could also seat the bullet out some and reduce pressures and increase velocity if it would chamber. In the case of AA 2230, 450#13 77/AA 2230 2311 fps 59453 PSI...... 450 NF FPS 75/AA 2230 2274 fps at 59661 PSI, a tad over 2000 PSI just because the North Fork is seated slightly deeper. Again, I might could seat out a bit and reduce this, add powder to increase pressures, and maybe velocity. If it would chamber. But then where to crimp on the North Fork, which right now has a wonderful crimp area on the new nose profiles, but if compressed enough, then crimp is not all that important.....

Lots of things to consider eh? I worry I might cause more confusion sometimes than answer a question?


Mike...................

Now just looking back on our 458 Lott data I see I reached 62700 PSI with 79/IMR 8208 and the 480 #13 Solid. And you state 82/IMR 8208 with a 500 Swift. I can't say about compression, but since the 480 #13 Solid is 20 grs less, and much less bearing surface, both factors in pressures, and we are at 62700 PSI already, then I would venture to guess that 82/IMR 8208 and any 500 gr bullet is going to be OVER MAX PRESSURE in your Lott, or any Lott for that matter...... Compressed is not the only component of pressures..... You have gone up 3 grs and increased bearing surface, and increased weight by 20 grs... Its over max I promise........ In this situation I would start looking at 75-76 grs of IMR 8208....

Now, concerning AA 2520..... Which I found a pretty good powder in 458 Lott. You say you are using 82/AA 2520 with a 500 Woodleigh and getting 2210 fps in 21 inches of Lott. I tested 80/AA 2520 with the 480 #13 Solid, again, less weight and bearing surface, and got 2294 fps and 58096 PSI in 24 inches of Lott. This is on the load data I posted for you guys..... What I did not show you was that I tested 86/AA 2520 for 2415 fps at 67071 PSI... Well over Max Pressures by 5000 PSI. I also tested 82/AA 2520 for 2343 FPS and 63417 PSI, slightly over Max pressures by 1000-1500 PSI. That with a 480. Now I am sure you are running over max with 82/AA 2520 and 500 gr bullet. Yes, your rifle is working with this, not sticky I am sure, and you are not seeing any outward signs of pressures, but it is there none the less, and over time will show at some point, first being your case wear. Don't go to 115 degree heat with that load...............

However, with all that being said, lets hope that Mike's AA 2520 is a little slower than my AA 2520 by a gr or two, but I have not seen that tendency with the AA powders...... So..... Tread carefully out there boys.....

Mike, I used 500 Swifts and 500 Woodleighs with good effect back in the day, but today no longer even have any in stock. Maybe you should also look at making a change? While right now we are only talking loads, powders, and pressures, but there have been far more work done on terminals that show these current bullets far out perform any conventionals.......... Just a thought.......

I hope this helped some, and did not cause more confusion????

Michael

Oh and by the way, I did a bit of work Wednesday in 458 Winchester, so posted new data on the B&M Site 11292013........ Bottom of the page....

http://www.b-mriflesandcartrid...tional-Research.html

FYI.........

Also just a note, the two photos of the "Lab Guy", that is kinda a joke from a few years ago..... Not anything actually serious.......... More FYI...............

Doc M,
Professor Emeritus of Ballistic Science (PhD-BS)
and Founder of MAAMI,

That lab guy looks familiar. The Oehler System 83 photographed nicely.

I always crimp if I can, and always strive to use the powder that gives some mild compression.
Loads are locked into consistency that way.

You did not confuse me. Perfectly clear, and fits my understanding and previous SWAGs.
Wonderful to see the actual pressure data we have mostly been SWAGging for so long.

Printed the new data for the .458 WinMag file. Nobody ever outgrows a .458 WinMag.
Even if they have a .458 B&M.

When do we get some more .458 B&M pressure data?
I am a greedy bastard.

RIP.....

(PhD-BS)......HEH....


Yes, you and I created the "Lab Guy" some time ago...... This is of course before the official
"Black" Lab Coats......

Most of the B&Ms do not require crimps, 500 MDM and 500 B&M do require them however.... I do always crimp 458 Lott and 458 Winchester as well...........

Most advanced handloaders understand what I was saying above, as RIP, I hope I don't confuse any of the less than advanced folks..... No offense to less than advanced handloaders, as my mission here is to do my best to help you guys....

458 B&M new data... Will have to check what I am short of, RIP, requests taken if I don't have something needed. I have a rifle set up permanent to do so....

Now, a tid bit of info.... As some know I am dead into this Blending of Powders with 500 MDM along with this project. With some success with blending RL 15 and RL 7 in the 500 MDM the last few days, I figured to give some blends a go in the 458 Winchester with the same mixes. I quickly found 75% RL15 + 25% RL 7 to be too slow, so I increased to 65%/35% with some pretty good success, equaling and surpassing most of the powders that we have already tested!!! I am currently at 2263 fps with a 450 gr #13 Solid at 55000 PSI... Not too bad! A blend of 50/50 I have taken to the top at 61000 PSI for 2280 fps, which bests all but two powders we have tested so far...... The 65%/35% may surpass the top powders......???? Or it might take a 60%/40% Blend??????

Just FYI ............ Messing around with something I could not let go of this morning, I had to know!!!!!!

M

These will do just fine. I have one 19.75" barreled .458 B&M, a couple of 24"-barreled .458 WinMags, and a 25"-barreled .458 WinMag that is now at less risk of being rebarreled:

This 20"-barreled .458 B&M is impressive:
400 Swift A ......... 67/IMR 4198 ... Fed 215 ... 2358
400 Swift A ......... 69/RL 7 ........... Fed 215 ... 2369
400 North Fork ... 69/RL 7 ........... Fed 215 ... 2339 ... Pressure 59587 PSI
400 North Fork ... 70/RL 7 ........... Fed 215 ... 2365 ... Pressure 63545 PSI

Even more impressive, 18"-barreled .458 B&M:
400 Swift A ...... 70/RL 7 ....... Fed 215 ... 2368


Hope to see some more pressures, any loads, any pressures.
I am a greedy bastard and it is no sweat off my brow.
I leave the sweating to the horny handed son of toil at the lab, who is so generous in sharing the knowledge.

24"-barreled .458 WinMag, very impressive for the Old War Horse:
400 North Fork Premium Soft
11/18/13 400 NF-Soft 70/RL 7 Fed 215 ......... 2369 .... 58105 PSI--Excellent Load
11/20/13 400 NF-Soft 67/H-4198 Fed 215 .... 2377 .... 60035 PSI
11/20/13 400 NF-Soft 70/RL 10X Fed 215 ..... 2368 .... 53288 PSI--Keg #1 Older Version
11/27/13 400 NF-Soft 72/RL 10X Fed 215 ..... 2389 .... 57735 PSI--Keg 2012 Version
11/27/13 400 NF-Soft 72/RL 10X Fed 215 ..... 2384 .... 55557 PSI--Keg 2013 Version
11/27/13 400 NF-Soft 75/RL 10X Fed 215 ..... 2453 .... 60129 PSI--Keg 2013 Version

Michael,

put these on your "To Do" list for 2014.

RUM wildcats.

338 Edge, 358, 416, 404, 458. I am buying 458 Reamers, so you could borrow that one.

Rich

This really makes for excellent reading and is a MUST READ for anyone owning these calibers - but in particular for .458WM owners.
For years we have been told that the .458 is underpowered, over compressed, runs at to high a pressure, case capacity is too small and is far in superior to the Lott round.
This testing doesn't validate any of those criticisms and it proves it is up there with anything else as far as dangerous game is concerned. If the .458WM isn't a DG round, then nothing else is either.
Don't get me wrong, I like all three rounds and would be happy to hunt with any, but, I confess I do have a soft spot for the .458 and in fact when I bought my CZ Safari I could've had it in .416 or the Lott. But I wanted the .458 so that's what I chose. I have copped a fair bit of critism for choosing the WM over the Lott, but I have NEVER regretted it and this data proves that all the so called problems it had are now gone. It does exactly what it was meant to do with no excess
pressure, compression and with good velocity.
Surely the .458 must now be beyond critism... and even amongst the various .416's, Lott's etc... it really is a formidable round..

Not to forget that it is easy to load the .458 WinMag out to .458 Lott length or longer in the CZ, using the longest monometal copper and brass bullets.
Even the longest of Talon-tipped CEB Raptor bullets can be magazine fed through a CZ with its 3.8" box.
But pity the brute who carries such a long and heavy rifle, eh?

The standard .458 WinMag throat is long enough for that also.
Any .458 WinMag with short box can be "Lott-loaded" single-shot style,
but the CZ 550 Magnum in .458 WinMag can be magazine fed, "Lott-loaded."
In fact, for best accuracy, with some bullets, long-loading might be required,
even though minute of buffalo is sufficient for most .458 WinMag work.

Just for interest, I was told by someone who's opinion and experience I respect 110% that for the .458WM, the 550gn Woodleigh's were the go for DG game.
After reading these results it seem everyone seems to favour the 450gn mono's.
The problem is, living down under, the only mono I can consistently get is the Woodleigh hydro.. but they are pricey and not always available and that last point is why I chose the 550gn weldcore.
I'm going on a Water Buffalo / Scrub Bull hunt in March next year and this gentleman gave me a starting load of 71gn of 2206h and a max load of 74gn 2206h behind the 550gn Woodleigh for a MV of 2100fps.
This load was worked up in the same rifle as mine (CZ550 Safari Magnum with a 25" barrel) and he assures me that anything it hits is immediately put on on its bum.
I have just started load development now and it's a pity that I can't get the same projectiles that are being tested in this topic. It seems that they do the same job being 100gns lighter and with less recoil. Oh well.. I'm sure the 550's will do fine just with a kick!
As a side note the gentleman I'm talking about was/is a former well known gun writer in Australia. He had a penchant for big bores and really liked the .458 but his real passion was for the big Weatherby's.. especially the .460.
I actually bought my CZ 550 .458 after reading his review on it in the 'Australian Shooter's Journal' magazine. This is where I got the load from too, but I contacted him personally about it as well. He told me that with the longer barrel and larger magazine length - being a magnum length action the bullets could be seated right out (thus more case capacity) and the usual result was 100fps more than with his other .458's. .458's have a massive amount of freebore and the limiting factor for bullet depth is the magazine length.
I was surprised when I asked him about crimping. He told me he doesn't bother with it! Ever! Not even with his .460. He told me he can't be bothered with it and never found it necessary and anyway he said the bullet sits on a full density powder charge and isn't going to compress into the case any further.
The only exception to crimping is with his .45/70 lever guns. These he crimps he says, so they feed reliability.
So, a bit of a bummer I can't get the Forthforks, but am confident the 550's will be fine... and, as Andy Runyun would say, when fired 'will back you out from under your beanie!'

RIP,

Mate you just beat me too it! Lol!

RIP........ I concur, 458 B&M is a good thing, in a small package. Two of my most favorite rifles are 18 inch 458 B&Ms.... One used this past July on buffalo, hippo, and probably my best elephant for ivory. It never came up short anywhere. The other a 18 inch stainless gun perfect for Alaska and has been to Alaska a couple of times. I do have some work to do with the 458 B&M, and have a plan to do so, try some RL 10X with the 400s, go ahead and do some work with the 370 #13 HPLG bullet, and probably some more. I see last update was March this year, and that was probably with the 250s.... I have to review some more the data sheet and see what else might be missing from it.


Rich....... I have a 358 RUM currently. Done data, but never bothered with pressure data. Big long heavy rifle, and I know I will never in my life take one of those out again, so while I have data, I have never bothered with doing any pressures..... Unless I currently have one of those big long 24 inch + guns here, I will never go to the trouble of building or purchasing another, as it will really be of no personal use to me. Sorry, but once you carry a 18-20 inch B&M around you become seriously spoiled from then on. Even when I just carry a 24 inch gun to the range I wonder to myself how in the hell I ever carried one in the field, and know without doubt I never will again, there is just no reason to do so.............. Somehow I just can't get inspired....

Michael

quote:

Just for interest, I was told by someone who's opinion and experience I respect 110% that for the .458WM, the 550gn Woodleigh's were the go for DG game.
After reading these results it seem everyone seems to favour the 450gn mono's.
The problem is, living down under, the only mono I can consistently get is the Woodleigh hydro.. but they are pricey and not always available and that last point is why I chose the 550gn weldcore.

BadBoy.......

458 Winchester has ALWAYS been at its best with 450s at better velocity. Any of these 450s will penetrate deeper than the 550 Woodleigh..... The 420 #13 HP NonCon will penetrate far deeper than the 550 Woodleigh, and do a hell of a lot more damage along the way.

My good friend Daryl Lenkic, Meplat Firearm Services, right there in Australia is the Cutting Edge Bullets and North Fork Bullets Dealer, and he will have all these bullets in stock, and if not in stock, he can get them for you, either CEB or North Fork...... Get in touch with Daryl, he can sort you out.....

http://www.meplat.com.au/index.../premium-projectiles



Anyone that does not believe that the 458 Winchester is more than adequate for any mission brought to it, is 20 years behind on their technical study. They read somewhere that the 458 Win could not run 500s at 2150, and that factory ammo was bad and so forth, and so on, and this was over 50 yrs ago when this happened when the 458 Win was introduced. Those days are LONG GONE........ Even before this bullet tech, there were superior powders developed, and someone recognized long before me that a 450 was the way to play in 458 Winchester. Someone still recommending 500s and 550s are behind the times and not up on their bullet tech........... For me, this even goes for the 458 Lott as well, there is just no reason in the world to run a heavier bullet than 450s. When these 450s cannot be contained in a broadside elephant, how much more do you think you need? When you get 6+ feet of penetration with these solids, how much more do you need? Of course, you never can have TOO MUCH penetration, but these 450s will NOT LEAVE you short of anything, therefore, the 458 Winchester cannot come up short for any mission asked of it!

Michael

Speaking of bullet tech and 458 Winchester..... On the data, you see I have paid some attention to two smaller, or lighter caliber bullets in particular...... These are the Cutting Edge 325 gr #13 Solid and the 325 North Fork CPS.. Cup Point Solid. Now, let me tell you about this 325 CPS from North Fork. This is not the heavy CPS, this bullet EXPANDS..... I place this bullet firmly in the NonConventional camp, penetration is fantastic. There are two Expanding CPS bullets in the 458 caliber lineup, a 325 and a 350 gr CPS... These bullets penetrate well into "Buffalo" territory. Yes, you heard me correct, these bullets have enough penetration, 325 and 350s, to hunt buffalo with!!!!!

Now, I have tested these soft points in 458s, 450 Swift, 500 Swift, 500 Woodleighs, and 500 Nosler Partitions. I have shot buffalo with the Swifts and the Woodleigh. Penetration of these Premium Soft Points in .458 caliber runs from 19 inches with the Nosler Partition, to 24 inches with the 500 Swift. 19 inches to 24 inches... Remember this, and these are tried and true buffalo bullets.............

Now look at these 325 North Fork CPS bullets............







Even launched at 45/70 velocities, they qualify............

I was so impressed with these bullets at the time, that John from North Fork and I designed this exact same concept for my .500 caliber rifles, and then later my .474 caliber B&Ms.... In .500 caliber we have a 450 gr and a 375 gr North Fork CPS..Expanding in which my son Matthew used the 375s on his big bruiser of a Australian bull buffalo, with great success, actually perfect success, finding two of the 375s on the far shoulder, fully expanding, and bull never went 20-25 yds max. That same year, 2012, I used a 425 gr North Fork CPS from my 475 B&M, dead on the shoulder on the best Australian Bull I have ever taken, and I have taken a few, and we did not recover that bullet, and still may be circling around in Australia somewhere..............

These bullets are more than worth a look, don't let WEIGHT fool you here, don't let your "Conventional" thinking get the best of you......... If you must, then back it up with the CEB 325 gr #13 Solid...




Michael

Wow!!!
Thanks Michael for addressing my question, specially so thoroughly.
You are correct, my AA2520 loads show no sign of over pressure, great extraction, no swelled cases or primer pockets, some of my cases have been loaded 1/2doz.times.(practice ammo) Shot this ammo in Rugers, Winchesters, Mauser's as well as my own CZ550. Primers showed no signs either, they looked great, heck factory Lott ammo from Hornady flattened out the primers more than my loads. Matter of fact, Hornady factory 500grn. Lott velocities in my rifle were 2220fps vs my loads at 2210fps. My goal was simply duplicating factory velocities with either the Swift A-Frame or Woodleigh 500grn, not out performing it...
I probably should have worded my question a bit different when asking if 82grs of IMR8208 would work without over compressing the powder with a 500grn.Swift.. I should have simply asked Would IMR8208 be able to make my desired 2210fps or so, and then would it be over compressed with the Swift's deeper seating depth.. Now here's where I need to add, can it do this safely as obviously I need to change my current data for the sake of safety..

But.... I love my Swift bullets & trust them immeasurably so I really don't want to give them up. In were as my experiences with Woodleighs have left me as a fence sitter in any debate of bullet effectiveness which is driving my desire to go back to my beloved Swift A-Frame's

Thanks again Michael, can't express how much we all appreciate and are learning from your work..

Regards..

Mike

Although I'm using different bullets your work tends to vindicate my own .458 Win loads. I'm getting 2350 fps with 78 grains of 2230 under the 450 grain Swift A-Frame and 2300 fps with 76 grains of the same powder under a 450 Barnes banded solid. Although different bullets are used it is nice to see that we basically ended up in the same place.

Michael, I'd like to ask a question, if I may.

You seem to draw the line at 65,000 PSI as your MAXIMUM allowable pressure...if true, why?

Have you ever correlated PSI reading with the PSIs at which primer pockets start to loosen-up quickly...say, too loose for a primer to hold safely after 5 reloadings.

I don't have PSI hook-ups on my guns, and I have been using "early primer pocket loosening" as a measure too much PSI.

Correlation with Quickload suggests that significant early loosening begins are 65,000PSI, and accelerates after 65,000 PSI.

What has been your experience?

Regards, AIU

Mike..... Very welcome.....Hope some of what we do here can help all you guys out.....

Dogleg....Your loads, AA2230 and 450 Swifts/Barnes are for sure all over 65000 or so, I would guess, depending on lots of factors..... Both these bullets have more bearing surface than the North Forks or CEBs, equals more pressures, and you are running them a bit faster than what I have been doing so here, trying to stay under 63000 with these 458s..... Of course, like Mike, your rifle is not showing it and obviously working fine.

With AIUs question, lets talk about top end and what it might mean actually.......

AIU... I think Max Top end for these 458s is 62500 or so PSI. As we know, most modern bolt guns will handle far more. During this testing about the highest I have had a load is 68000 PSI, and of course it worked just fine. Primers were not flattened excessively, rifle worked fine, opened easy, no real outward signs. I forget what powder or load that was just off hand, but with some powders you can get 68000-70000 in a rifle and show no signs, other powders or bullets, you might get the same pressure, but dynamics of the type burn will cause signs of pressure, even sticky bolts.

I draw the line with my B&Ms, based on RUM and WSM cases at 65000 PSI MAX PRESSURE..... And sometimes this depends on a particular rifle as well and or powder/bullet combo. If you are running 62000 PSI and the bolt is sticky, that is not good, regardless you have to back down. This could also be caused by faulty brass. Brass normally can take 7000-10000 PSI on its own, before the rifle takes over. I have had some loads with normal brass, say Win or Rem brass, and then have a run from a smaller manufacturer that could not handle what the Win or Rem brass could, and get horribly sticky, to the point of being a problem, even though you are under Max Pressures..... There are LOTS of variables that come into play that must be considered.

See again below what Ken Oehler has to say about Pressure........

quote:

Chamber pressure measurement is a blend of science, black art, and common sense. There are few absolutes; the best we can expect is to reliably distinguish between the safe and the unsafe. Pressure measurements are tedious, but they must be made.

How true.... There are just NO ABSOLUTES.... Today, with my rifle, powder, bullet I may tell you a load is doing 62000 PSI and it is safe..... IN MY RIFLE, WITH MY POWDER, and other components... Your Powder is Not My Powder.......

Just YESTERDAY I discovered a couple of issues with our current data we are working on now. Remember those two 1# cans of AA 2230 I just got in last week or so?????? Well, in 2011 I had a 2011 version of AA2230, which 74 grs gave me 2341 fps with a 450#13 Solid and worked great in the same rifle I am using now to take pressures. Last week doing the pressure data with one of the new cans of AA 2230 74/AA 2230 with same rifle, same 450#13 Solid gives us 2222 fps and 57281 PSI. This is 119 fps less with the same amount of AA 2230. Difference between 2011 version and 2013 version..... ?????? I had to use 77/AA 2230 to get to 2311 fps at 59453 PSI.

What version is your AA 2230????? Why do they always tell us to start 10% less than stated or published? I think there is good reason for that.

In addition to AA2230, remember I got a new 8lb can of X Terminator last week as well, or the week before I don't recall. XTerm is decent powder, but never really found something perfect for it in the B&Ms, so I have only ever had 1 One# Can, which is nearly used up. Recently I found it was doing a pretty decent job in my new 500 B&M, and then we started our little 458 Lott/458 Winchester Project, and X Term is a contender here as well. So I figured I could not go too wrong getting a new 8# can of it, so I did.

With this new 8# of XTerminator I have been busy over the last few days working loads with the 2 450 gr North Forks, FPS and Soft. Finished actually yesterday morning and 76/X Term with the 450 North Fork Soft gives us 2305 fps and 61538 PSI... Safe Max Load (we will talk about this term "Safe Max" shortly) With the 450 North Fork FPS 75/XTerm for 2270 and 57989 PSI is Max Safe, 76/XTerm put us at 2298 and 63370 SAFE MAX.... A jump of over 5000 PSI with one grain, and I want under 63000 PSI for Safe Max in 458 Win.... In looking back at data done middle of November with that 1st can of XTerm I had, I see that 71/XTerm with the 450#13 Solid give me 2258 fps and 62498 PSI Max Safe.... Now we know that we can always run a tad more powder and velocity with the 450#13 than the North Fork because of seating depth and a few other things that we already discussed. Now I can run 4 grs more XTerm in the North Fork than the #13??? NO I don't think so.... We are seeing a difference in Powder between 2011 and 2013, same as we saw with AA 2230. I would test that today if I could, but I am totally out of 450#13 Solids, and have 250 on order to finish this project. Soon as they come in, I have to run new data on the 450#13 With this NEW XTERM.....

My Powder Ain't Your Powder

Please remember these things............

AIU.... Loose primer pockets after so many firings is for sure an indication of pressures, loosen too quickly, say 2-3 firings, then you are very high, likely more than 65000 PSI... 5-6 firings, maybe close to 65000 or so. But again, these variables start to take effect, brass, maybe Rem or Win made a shitty run of brass? Maybe too soft? Maybe to hard? God knows all the variables that can come into play here.......

I have always had an interest in pressures, its always been such a mystery, and can sometimes still be a mystery of some of the wild things you run into that even running gages can't explain properly. One way is to measure cases before and after firing. This can be an excellent indicator of pressures I have found. Some say not, some say yes and so forth, however the problem is HOW MUCH IS TOO MUCH?? When it comes down to it, no one could tell me exactly how much I was to measure on a particular case or caliber to say if I had an increase of .001 or .0025 that it was too much, or not enough? Some of these things I had to learn the hard way. Belted measurements are different than rimmed, rimmed and belted different than rimless and so on, even caliber comes into play when measuring pressures.... Let me explain.....

Early on in the B&M program I learned how to measure the cases of the bigger bores, 416-.500 by trail and error. Remember, this brass is RUM brass, so I measured just above the groove so I would have a consistent measuring spot. I was way too lazy to start hooking up strain gages and doing that, so I was measuring brass, observing the other details, primers and such, and of course listening to what my rifle had to say as well. I began by going up to a .0015 increase and that was very safe and showed zero signs of any pressures at all. Soon I took it to .002 increases, still good to go. Then I took the big bores to .0025 increases, and when I got to that point I started seeing pressures, rifles started speaking to me and so forth. I continued on that path for some time.

Soon young Aaron Carter was writing for one of the NRA Magazines, and got very interested in the 458 B&M. Through conversations he was concerned about pressures... Crap, I kept telling him the loads I had were safe and good, but being young he had concerns. So damn, I decided I had to do something different, so I dragged out the PT 1, started putting strain gages on rifles and went to work...........

Well, I found I was not as stupid as I might look sometimes, and my measurements of .0025 were pretty much spot on the money. These loads were up there around 60000-63000 PSI, and I had set a full Max Load at 65000 PSI, Safe Max at no more than 63000 PSI.. Pretty much all my loads were dead on the money and only a few exceeded 65000 PSI and were brought down to Safe Max Levels..... Many of my 400 gr loads were in excess in the 416 B&M, running upwards of 70000 PSI, all these had to be brought down considerably, most of the rest were in good shape.

Then along came the 9.3 B&M. .0025 measurements were just not getting me where I thought it should be. So I bought some factory ammo in 300 WSM and 300 RUM, and 338 RUM. I measured all this factory ammo and it was going to .004 to .005 increases without issue????? I hooked up the gages on the 9.3 B&M, and found that at max safe levels, 62000-63000 PSI I was getting .0035 increases before and after firing. So dropping in caliber changed the dynamics of what I needed to measure and how much.

If running a factory round, then you can purchase some factory ammo, on rimless measure just in front of the groove. What you get on factory ammo, do not exceed those measurements, at least not by much........

On belted cases, they tell me to measure the belt, and an increase of .001 is max. Looking back at my data I see there are some issues with this, so that is not exactly absolute either. I measured belt, and just in front of the belt. Finding that just in front of the belt an increase of .0015 was normal, more than that???? On one load that gave 68000 PSI only measured an increase on the belt of .0005, and 68000 is over max safe.....

Rimmed? Still really don't have a good handle on that... to be honest.... Sam and I did some good work on 500 Nitro and doing some measurements, really need to look at that... But currently writing this I have forgotten exactly those numbers.....

MAX SAFE PRESSURES....... This is one of my own terms and comes from being safe in the field under all sorts of conditions. It is of course not absolute, as nothing of what we do with pressures is absolute. But it is a step to being safer in the field. Especially with our big bore rifles, and the purpose they have in store.... Dangerous Game Rifles and Cartridges!

We don't want to go to Zimbabwe with our loads at full MAX PRESSURES of 65000 PSI... Why? I don't care if we have heat sensitive powders, it might be a 110 degrees in November and we are getting ready to bust a elephant at 10 yards, what happens if one of those wild ass variables comes into play, and our round for whatever reason peaks out at 71000 PSI instead of 65000 PSI, and our gun locks up???????? We better be damn good and have that first round do its job, because if not, our PH is going to have to pick up the slack!!!!!!!!!!!!!! And that is BEST CASE SCENARIO in that situation, far worse things could happen......

I have to go for a bit, but I want to continue this shortly.............

To Be CONTINUED:....

M

quote:

Originally posted by michael458:

Early on in the B&M program I learned how to measure the cases of the bigger bores, 416-.500 by trail and error. Remember, this brass is RUM brass, so I measured just above the groove so I would have a consistent measuring spot. I was way too lazy to start hooking up strain gages and doing that, so I was measuring brass, observing the other details, primers and such, and of course listening to what my rifle had to say as well. I began by going up to a .015 increase and that was very safe and showed zero signs of any pressures at all. Soon I took it to .002 increases, still good to go. Then I took the big bores to .0025 increases, and when I got to that point I started seeing pressures, rifles started speaking to me and so forth. I continued on that path for some time.

M

Doc M,

Thanks for the latest chapter.
I like that expression "by trail and error" as it sounds more like a "hunt for truth" than a legal proceeding.
But you need to correct one typo above, as we understand you did not expand a RUM case head by 0.015" and meant 0.0015" instead.
Best to eliminate that kind of typo before the book goes to the proof readers.

quote:

as we understand you did not expand a RUM case head by 0.015" and meant 0.0015" instead.

RIP... Thanks for that correction, just typing a little too fast this morning to catch that one. It is corrected now, at least the only one I saw.......

Yes, sometimes a lot of trail and error, on some of these things I read every book I could get my hands on, and while some things were address, most were not. For the life of me I could not find anyone that could actually tell me where to measure, how much was too much, how, what when nothing..... So sometimes you have to learn these things yourself. We here are still in the learning phase, and suspect that we always will be on many things.........

M

CONTINUED:..... Another chapter...... LOL....

OK, I was talking about my term, Max Safe Pressures. While we may have a cartridge capable of Max Pressures of 65000 PSI, that does not mean we need to run 65000 PSI all the time. Fact is, we need to stay
below that Max for many reasons.

One of the most important is the example above, being on a major DG Hunt, and have a pressure issue, this could cause a lot of serious problems.

A really good load can and does have Extreme Spreads from shot to shot. Our chronographs will not show us this all the time. It is entirely possible, and even "Probable" that our loads will show tiny, very small extreme spreads on the chronograph in velocity, however our pressures can have large extreme spreads. A good load will show Extreme Spreads in pressure of 2000-2500 PSI. Marginal loads can be much more, 5000 PSI +. And you will not see this on the chronograph, only on the pressure equipment. Now how it is possible to have such an extreme spread with the pressure, and not always show on the chronograph I really cannot tell you, seems we would see more, but we don't, I have shot 1000s on top of 1000s of rounds doing pressure traces and see it all the time. Now a 5000 PSI swing with one load can be a problem if you are working off an average of full Max Pressure, whatever that might be for a certain cartridge. I consider RUM and WSM cases max at 65000 PSI. I remember somewhere in the last week or so, 458 Lott and 458 Winchester being 62500 PSI Max Pressures. So for this data, I chose anything under 63000 as being absolute max... If it reads 63000 Then its over on this work. Our rifles are the same, 458 Win or something in RUM, so the rifle can most certainly handle 65000 or more. But running at MAX PRESSURE, and we have one of those 5000 PSI swings, then we are over 70000 PSI. Most proof loads run 75000 PSI or so, but only one of those is ever shot in a rifle.

What would be Max Safe in a 458 Lott or 458 Winchester, 416 Remington as well? I will hang with 62500 as Max Pressure, and 59000-60000 PSI as Max Safe Pressure, to give you just a tiny bit of working room here. And this of course depends on many things, one thing I want to point out is a load I worked on yesterday morning quickly with the 450 North Fork FPS and X Terminator. I loaded 75/X Terminator with both the 450 North Fork FPS and Soft point. 75/X Terminator and 450 FPS gave me 57989 PSI, with the 450 Soft I got 58058 PSI. So I figured I could go easy to 76/X Terminator with both and did. 450 NF FPS with 76/X Terminator gave me 63370 PSI, just one gr jumped the pressures over 5000 PSI. The 450 Soft with 76/X Terminator gave me 61538 PSI, under Max of 62500 PSI. So, Max with the 450 Soft I have at 76 and Max with the FPS at 75. Now, Max Safe we can stay at 75/X Term with the FPS, this gives us some room to work with, and Max Safe would be dropped to 75 with the soft as well... So both those would be around 58000 PSI Max Safe Load to give you some working room, Hot days, Extreme Spreads or other variables that can work their way into your loads........

This is what Max Safe means to me and the way I define it. So you will see that in the data that is coming up and final loads settled on. It would be wise I think to pay some attention to that......

You know, we all get caught up on getting as much as we can from our cartridge, especially in terms of velocities. We want top end! Its in our nature, and I get caught in it too just as much as any of us. But what we have to realize is that going to the very top end of every thing we do is not always in our best interests. We must consider the bullet we are using! If we are using for example a Woodleigh soft, that is designed to work great at 2150 fps, and we push it to 2300 fps, is that in our best interests? Will that give us MORE MORE MORE? In some cases, it will actually give us LESS. In almost every single case running a conventional bullet, premium or otherwise, More Velocity does not actually give us more performance, and in all but one case I know of, it gives us LESS PERFORMANCE. So do we really wish to be at top end pressures and velocity? They go hand in hand 95% of the time, more velocity, more pressure! NonCons and todays modern Solids is another story, you do get more with more, but to what point? For me, I will give up that 30-50 fps, bring pressures down to 58000 or so and keep it in the safe margin. And these are things you need to consider, there are so many variables out there that we cannot control when it comes to pressures, I think its best we stay on the safe side of pressure when we are in the field, hunting dangerous game. You know, other things, no big deal really, so what if you loose that 15 point buck because of a pressure issue, so what if you are sitting at the bench shooting and things get a little sticky, lives are not at stake here, so you might choose to push the envelope if you want, but in the end, what do we really gain for just a few fps edge?

We as shooters need to consider "Slowing" down just a bit for many reasons............

Michael

Want to see some Blending Tests? HEH HEH..............

I went a little nuts Saturday morning, got some blending 458 Winchester on my mind, and could not
let go, I had to see............

So, what sort of blend would one do? And how would you determine what sort of blend you would need?

I wanted something for the 450 gr #13 Solids, so I would need a base powder that was a bit on the slow side, and then add some faster burning powder to bring the rate to the point I wanted. Now I am a novice blender and still learning, but I figure if one is going to blend, to keep things in a mix then granules need to be pretty close to the same. I don't think one would want to blend a ball powder with a stick powder and such as that. So we know that this batch of RL 15 I have is very slow for 458 Winchester, in fact I don't think we can get enough or compress enough in the case to run pressures up with any amount. So I picked RL 15 as my base powder. Now, what could I speed this mix up with to be able to get enough in the case to make a difference? Hmmmm, well, easy, how about some RL 7? I think that might work............

Lets start with 75% RL 15 and 25% RL 7! 70 grs should be a safe starting point to get a data base from........ This mix gave us 2114 fps and 47000 PSI... Moving to 73 grs of this blend it took us to 2185 fps and only 48887 PSI. Well, still a little bit too slow, and one can quickly see we are not going to get enough in the case to bring velocity up that much, although, if you could go to say 75 grs or so then that would take it over 2200 and be a very nice, compressed, safe well under pressure load, but that was not my goal on Saturday, I wanted MORE.............

Next step... 50% RL 15 and 50% RL 7.........
Again, 70 grs should be a safe start and that gave us 2210 fps at 52772 PSI... An excellent start! And not a bad load on its own. Going to 73 grs however jumped pressures considerably to a full 61537 PSI for 2280 fps. This load matches most of our very best loads we have tried so far, with standard powders. It was also very consistent and as good as anything we had so far... But at 61537 PSI this was the upper end, so it was over......

Hmmmmmm?????? OK, how about we try a 65% RL 15 and 35% RL 7 blend? Again, starting at 70 grs this gave us 2143 fps and 49005 PSI.... 73 grs gave us 2216 fps at 53415 PSI... Not bad....75 grs gives us 2263 fps and 55625 PSI, excellent pressure traces, very close Extreme spreads in pressure, and excellent load. Velocity is up and not bad at all in comparison to what we have already done! I am excited... Next Step.. 77 grs.... A full 2311 fps and 61869 PSI AVERAGE... But I don't like what I see here, one trace at 64850 PSI OVER MAX and the other at 58888 PSI... 5961 PSI Difference? I don't like this... RETEST, and test at 76 and 77, include the Oehler as a check too.........

Ok, now we are loaded again with 65% RL 15 and 35% RL 7..... 76 grs.... Our Velocity 2275 fps and PT 2 says 60142 PSI. Very good.... now, 76 grs with the Oehler... 2272 fps and 60100 PSI with the Oehler. Don't get any better than that....... Very tight numbers.......

65% RL 15 and 35% RL 7....... 77 grs ReTest.... PT2 gives us 2288 fps and 60323 PSI??? Hmmm??? Not much more than the 76 load? The Oehler gives us 2298 fps and average of 64000 PSI even. Both have exactly the same ES at 1103 for PT 2 and 1100 for the Oehler, but pressures higher with the Oehler? But, look at the velocity, it is also higher, not by much, but this explains why the Oehler is giving higher pressure on this one.

Now, take a look at the difference in pressure from 75 grs to 76 grs with this 65% RL 15 and 35% RL 7 blend. 75 grs gives us 2263 fps and 55625 PSI. Going to 76 grs only gives us 2275 fps, a mere 12 fps gain, but pressures got to 60100 PSI or 4475 PSI for that 12 fps........ To me, that 12 fps is not worth the extra pressures. We do not see major gain in velocity, but do see fairly large jumps in pressure! Best load with this blend is to stay with 75 grs.... And forget the rest..... A very good Max Safe load......

With this info, I figure optimum blend would probably be something like 60% RL 15 and 40% RL 7..... But at this point, I think time better spent would be to look for another blend...... Very interesting stuff, at least to me.... In very short order we had a powder blend that equaled some of the best we had already, not bad.....

Just FYI and for fun.......

Michael

Michael, great answer! Thanks for sharing all that experience. I really appreciate it.

I have a follow-up question, if I may.

Have you correlated Quick Load predictions with your actual measurements? Basically, I'm asking...how good is the QL internal ballistics program in your experience?

Warm regards, AIU

AIU.... Very long winded answer I am afraid..... HEH HEH...........

I have Quick Load, and its a hell of a good program.. To get you started! To help find a starting point with a particular powder. However, one cannot rely on it for actual pressures or most of the time actual velocities. Sometimes it is close, but that would be 10-20% of the time. Most of the time I find its estimates high.. Example, if it says 55000 PSI, then more than likely its going to be 50000 PSI. But nothing you can count on 100% of the time either. For that less than likely time it might be close........

When I look at QL for a starting point, I normally pick one of the powders I have on hand, that will be suitable for my mission. Then I pick a starting load that is from 50000 to 55000 PSI and start with that..... I have yet to have it be over the stated pressures....... This has been my experience.

One of the things QL does is assist in picking some of the best powders for your application, very good tool for that.

QL can get you off to a good start............

Jim, Capoward, is the QL Master here, and maybe a good one to ask to run some numbers for us, compare what I have on some of the data, compared to what he comes up with on the QL...?????? Jim???? Might be a good exercise for us? One of the big deals is getting the seating depth the same on QL as in reality. So I can provide some of that info Jim might need.....

Michael

Michael, thanks again for your response - very helpful.

In regards to the QL fit to actual data, there is the so-called "WEIGHTING FACTOR" on QL that can be adjusted within the the program to fit better with gauge measured PSI data.

The "WEIHTING FACTOR" is a nebulous variable in the program to make adjustments of the amount of unburned powder and gases that travel down the barrel with the bullet as the bullet accelerates.

QL suggests reasonable default values of ~0.75 for cylindrical straightwalled cases (i.e., big bore and pistol cartridges), ~0.50 for your average bottle-neck cartridge (i.e., 30-06), and ~0.33 for overbore bottle-necked cartridges. I would expect each cartridge to have an optimum "WEIGHTING FACTOR".

You might be able to get a better fit between QL and your gauge-measured PSI/velocity data by adjusting this factor.

I haven't done this, since I don't have actrual measured PSI data to make a more scientific estimate of what this factor should be.

Please forgive me, if you've tried all this before.

Regards, AIU

AIU,

I'm on my iPad so very likely will generate very long sentences. I apologize for that.

A few years ago I adjusted the QL weighting factor for a number of the B&M, but especially the 500 MDM. Adjusting the weighting factor in conjunction with the start pressure levels for the, new at that time, brass BBW#13 bullets allowed me to match a number of Michael's loading within his documented ES levels.

Of course Michael provided the exact 'overflow water capacity' of each of his cartridges, fully form fired and resized just before loading which allowed me to save a specific case data set for the QL work. This is critical to obtaining the most accurate QL 'run scenarios' possible.

Change powder lots, or powder, and a weighting factor adjustment will generally get the QL run close to Michael's new ES data again.

Now that Michael is running updated data it would be much better to adjust the burn rate data for the specific powder first, then adjust the weighting factor second.

Ah before I forget, my current version of QL came with the B&M cartridges loaded within the data set so when I updated the program I also lost all of Michael's 'overflow case data'. Cartridges were exactly named so no way to preserve the original data.

Before embarking upon a QL data match scenario with Michael's lab work I would recommend purchasing and installing the very latest QL on the market.

Once the newest QL is installed you can adjust the specific case data, just remember to name the case other than as installed by QL.

Adjust the burn rates of the specific powder being used - and rename by maybe including the lot number and mfg date.

Once case and powder are adjusted you can tweak the weighting factor for the renamed cartridge until you match Michael's specific loading.

Once all is accomplished you should be able to run Michael's lab data in QL and produce data within the documented ES for velocity and pressure.

Without adjusting case capacity, powder burn rates, and weighting factor for each ease QL will give 'average estimates' similar to a reloading manual but nothing within an established ES for your firearm.

Oops almost forgot. It is usual for QL to give a slightly different result reading for the identical run scenario so just keep track of them and use as an projected ES for the specific cartridge.

I hope this helps...

Just got a question in regards to blending powder.
Do you load one powder in the shell first then the other?
or
Do you just blend the two powders together (in the right ratio) then load the blended powder in the shell?

Thank you!

GB,

Russ.

Badboy......

I am mixing the blend together, shaking and baking...

Blending is like searching for treasure, there is a magic mix out there for these big bores, but it is proving to be very elusive. So far I have been able to match and equal, but not exceed by enough to make it worth the effort involved, yet I enjoy the discovery part of it. It is not practical without having the equipment I have to even consider time spent doing it. I have come up with better loads, tighter curves and pressures with some mixes.......... But for the joy of discovery, its not worth the effort, YET.........

I think I have most of the basics done with both 458 Lott and 458 Winchester, I plan on loading up the entire line of bullets in 458 Winchester cases, maybe this morning, taking some photos, posting them for you so you can see where I was seating to, and what I have been working with. Then I suppose I have to get a gage on one of the 416 Remingtons, and possibly by next week start some work on that. If there is anything I have missed in either of the 458s, let me know. I intend to post new data sheets this morning as well to catch everything I have up to date, as of yesterday.....

Michael

Here is our 458 Lineup...............

I am sorry guys, but I just uploaded new data to the B&M site.... I know many have already downloaded, but I had some updates to do before final. As I start work on 416 Remington next week I may still do some work with the 250 Socom in 458 Winchester, but pretty much everything I can think of or do has been done now in 458 Winchester and 458 Lott, unless someone has some requests.

Still on plan is doing some tests with different primers and some other possible things within this same data, so we are not finished by any stretch.............

New data here............

http://www.b-mriflesandcartrid...tional-Research.html

Michael

Michael

What are the chances of finding Norma and/or Vihtavuori powders where you are at?

I know for a fact that there will be "Michael McCourry worshiping shrines" built across Scandinavia if you manage to give us some pressure tested load data for the .458 Lott using Norma and Vihtavuori powders.

Once again, Thank You Sir for the work you do!

quote:

Originally posted by Klein:
Michael

What are the chances of finding Norma and/or Vihtavuori powders where you are at?

I know for a fact that there will be "Michael McCourry worshiping shrines" built across Scandinavia if you manage to give us some pressure tested load data for the .458 Lott using Norma and Vihtavuori powders.

Once again, Thank You Sir for the work you do!

I could get into this worshiping thing! How much does that pay ya reckon?



I have on hand VihtaVuori 140, 160, 550, and 560........ I don't have any Norma. What powders are you guys using in the 458 Lott or Winchester for that matter, and if I can find some we will take a look......... At some point, if I get on the lists we can find some of whatever I think...... Midway has Norma listed, some, of course all out of stock and no backorders, so at some point we can find some.... Now, what powders do we want to look at????

Michael

quote:

Originally posted by michael458:
I am sorry guys, but I just uploaded new data to the B&M site.... I know many have already downloaded, but I had some updates to do before final. As I start work on 416 Remington next week I may still do some work with the 250 Socom in 458 Winchester, but pretty much everything I can think of or do has been done now in 458 Winchester and 458 Lott, unless someone has some requests.

Still on plan is doing some tests with different primers and some other possible things within this same data, so we are not finished by any stretch.............

New data here............

http://www.b-mriflesandcartrid...tional-Research.html

Michael

Thanks for the excellent work Mr. McCourry! See ya in Dallas!

quote:

Originally posted by capoward:
AIU,

I'm on my iPad so very likely will generate very long sentences. I apologize for that.

A few years ago I adjusted the QL weighting factor for a number of the B&M, but especially the 500 MDM. Adjusting the weighting factor in conjunction with the start pressure levels for the, new at that time, brass BBW#13 bullets allowed me to match a number of Michael's loading within his documented ES levels.

Of course Michael provided the exact 'overflow water capacity' of each of his cartridges, fully form fired and resized just before loading which allowed me to save a specific case data set for the QL work. This is critical to obtaining the most accurate QL 'run scenarios' possible.

Change powder lots, or powder, and a weighting factor adjustment will generally get the QL run close to Michael's new ES data again.

Now that Michael is running updated data it would be much better to adjust the burn rate data for the specific powder first, then adjust the weighting factor second.

Ah before I forget, my current version of QL came with the B&M cartridges loaded within the data set so when I updated the program I also lost all of Michael's 'overflow case data'. Cartridges were exactly named so no way to preserve the original data.

Before embarking upon a QL data match scenario with Michael's lab work I would recommend purchasing and installing the very latest QL on the market.

Once the newest QL is installed you can adjust the specific case data, just remember to name the case other than as installed by QL.

Adjust the burn rates of the specific powder being used - and rename by maybe including the lot number and mfg date.

Once case and powder are adjusted you can tweak the weighting factor for the renamed cartridge until you match Michael's specific loading.

Once all is accomplished you should be able to run Michael's lab data in QL and produce data within the documented ES for velocity and pressure.

Without adjusting case capacity, powder burn rates, and weighting factor for each ease QL will give 'average estimates' similar to a reloading manual but nothing within an established ES for your firearm.

Oops almost forgot. It is usual for QL to give a slightly different result reading for the identical run scenario so just keep track of them and use as an projected ES for the specific cartridge.

I hope this helps...

Jim, what weighting factors did you derive from that work? I'm especially interested in the .375 and .416 caliber cartridges. Regards, AIU

Hi Michael,

Once again THANK YOU for all the work you I have done, in particularly for the .458 WM.

As I work for a church I cannot actually worship you coz I'm not allowed, BUT, you keep this up and you'll nearly be there..

Is there any chance you could or have tried the Woodleigh Hydro's? From what you have told me they should work well in the .458WM/ Lott as they weigh 450 or 470gn and are a mono design. They seem to tick all the boxes and they claims made for them are amazing.
Also, as they are made in Australia (only a couple hours from my house actually) it would be good to buy local and support Aussie made products... if they are any good that is!
If you ever get around to testing them I would be watching with VERY keen eyes!

Cheers mate,

GB Russ

Not meaning to beat a dead horse, but most of the R/L canister powders can be, and often are, "factory seconds". Burn rates on those powders made by Bofors often vary 5% from lot to lot.

The situation is better with those (R/L-17 and R/L 33) that are made by another RUAG subsidiary in Switzerland.

Norma it seems, gets first crack at the Bofors powders. They require much tighter consistency than R/L.

A careful look at a good burning rate comparison chart will pretty much show which Norma powders correspond to which R/L powders. I am just using up my R/L powders (except for R/L 22 - that I gave away) and going with Norma.

L/D

PS Keep your eyes peeled for the new Norma reloading manual; it should be out in two to three months, perhaps sooner (I hope).

I believe Western Powders has acquired the Norma line now.