quote:

Originally posted by Biebs:
IS IT DONE YET ????????

...

Well, just heard from AI via Michael that they do not need to wait on the action and barrel to start working on the stock blank. So, this cuts the time in half. It will probably be ready very soon after yours.

Great!

Cold you post the approximate rifle weight and load with 450s? I'd like to run it through a recoil calculator just to get a feel for whether the buff would be the only one turned inside out.

quote:

Originally posted by Dogleg:
Cold you post the approximate rifle weight and load with 450s? I'd like to run it through a recoil calculator just to get a feel for whether the buff would be the only one turned inside out.

Looking at Michael's website – the typical 500 MDM weights 8-8 ½ lbs and the 450s run between 2500-2550 fps MV.
Here’s the website link: http://www.b-mriflesandcartridges.com/default.html

quote:

Originally posted by Dogleg:
Cold you post the approximate rifle weight and load with 450s? I'd like to run it through a recoil calculator just to get a feel for whether the buff would be the only one turned inside out.

Dogleg, the numbers don't tell the full story.

I'm loading mine up to 2400+ with the 450gn Raptors with fairly comfortable recoil.
I would suggest it is about on par to a hot loaded Lott, maybe only slightly more.
I believe that the shape and style that Accurate Innovations cuts these stocks helps minimize recoil.
I have no science nor proof but I believe the aluminium bedding chassis may also contribute to the level of comfort felt by the shooter.

(or maybe my recoil sensitivity has been pounded into oblivion !)

I would rate these rifles in this caliber as being little different in felt recoil to a properly loaded Lott.

I certainly know that my .500 double producing almost identical numbers kicks substantially more and weighs a pound more rifle weight.

Well, the AI stocks with their built in aluminum chassis is supposed to help absorb the recoil. My stock is also getting built with an 8oz mercury reducer, and 1" Pachmayr Decelerator.

Of course, one can also train oneself to handle the recoil.

quote:

Originally posted by Paul Truccolo:

quote:

Originally posted by Dogleg:
Cold you post the approximate rifle weight and load with 450s? I'd like to run it through a recoil calculator just to get a feel for whether the buff would be the only one turned inside out.

Dogleg, the numbers don't tell the full story.

I'm loading mine up to 2400+ with the 450gn Raptors with fairly comfortable recoil.
I would suggest it is about on par to a hot loaded Lott, maybe only slightly more.
I believe that the shape and style that Accurate Innovations cuts these stocks helps minimize recoil.
I have no science nor proof but I believe the aluminium bedding chassis may also contribute to the level of comfort felt by the shooter.

(or maybe my recoil sensitivity has been pounded into oblivion !)

I would rate these rifles in this caliber as being little different in felt recoil to a properly loaded Lott.

I certainly know that my .500 double producing almost identical numbers kicks substantially more and weighs a pound more rifle weight.

I ran the numbers, just to compare against my .458 with 450s at 2350 and 500s at 2200. At similar weights I suppose they would at least in the ballpark which is quite doable. At least there is a point where they aren't in totally different worlds, even if one is just getting started and the other is well and truly maxed.

This is going to take some pondering.

It's very difficult for me to relate recoil to you guys, so I am pleased Paul tuned in, and I concur with Paul on everything he conveyed. The 500 MDM will get your attention at the bench without proper gear, but in the field I never feel it or hear it or even pay it the least attention, it is just not an issue. With gear it is not even an issue at the bench, I have literally shot 1000s of rounds of 500 MDM from the bench doing test work. It has all you need and then some more, and the best thing is, it is not a big platform. A 20 inch standard rifle will be 41 inches overall, and come in at 8.5 lbs MAX, more likely 8.25....... Two of my 500 MDMs are 19 inch guns and are an inch shorter. I still have the second rifle done as a test platform with strain gages, it still has a 21 inch barrel.

At 20 inches it comes in 4 inches shorter than my 24 inch 458 Lotts, but 1.75 to 2 lbs lighter. Believe me, both these numbers become substantial when it comes to handling the gun, and of course running around in the bush...

One mention, especially to Tanks, remember, these are true .500 caliber, and there are a lot of cheaper bullets out there that one can practice with, drop velocities down, and even hunt deer/pigs and such with, and be extremely effective at reduced loads. Hell, some of these aren't much more than shooting a .500 caliber 22...... HEH....
I wish I had time to do more fun reduced play loads, I keep thinking of it, but seem never to actually get to it. Always something else to do here.......

This morning I started getting serious about looking at POI on different bullets in the 500 B&M (basically a 2.5 inch 500MDM)..... On average the 500 B&M falls short of the 500 MDM around 150 fps, maybe 200 fps with some bullets. Its only advantage is that being 2.5 inches, one can load those long nose projection #13 Raptors and add a Talon tip to them, run them through the magazine. This picks up the 500 B&M at impact velocities at 50 yards by 150 fps, so at 50 yard impacts with these type projectiles, the 500 B&M comes close to equal with the 500 MDM. But go to any other bullet, the 500 B&M comes short.... So it is a very specific rifle for a purpose, which is for me to play with. HEH....... It is the same RUM action as the 500 MDM, but only an 18 inch barrel, and smaller contour barrel, same as the 50 B&M.... I will be taking it to Zimbabwe in June to back up Mark David with his 475 B&M Super Short..... I doubt I will have to back up anything, but that is a good excuse anyway........

Here is the 500 B&M compared to the 500 MDM.......... Just FYI.....



This morning I fired 50-60 rounds through it checking POI for several different bullets;
One of the main bullets I want to look at is a 410 gr #13 Raptor, with added tip. Running this bullet at 2510 fps currently with a heavy dose of X Terminator...

Right now these are my contenders that shoot close or same POI.....

410 Raptor--2510 fps
450 North Fork CPS--2385 fps
450 North Fork FPS--2387 fps
450 #13 Solid--2356 fps

Actually all 4 of these bullets are max 3/4 inch apart Elevation--Windage Perfect in line at 50 yards....

I looked at the newer 475 and 525 #13 Solids, but they were just a tiny bit too far out. Interesting the 500 B&M can run that 525 at 2175 fps... Not shabby for a little gun.... But the 500 MDM is at 2320 fps with that 525 Solid...

Also don't forget we have done a lot of light for caliber Raptors that are excellent in the 500 MDM, one of the best I like is the 335 #13 Lever Raptor.. Seat Deep, add Talon Tip.... 2910 fps at 60000 PSI.... Would turn anything thin skinned inside out.... Lion/bear, any plains game and such...... I used this in Australia last year with Paul on some of those buffalo.... It did not come up short even with that heavy duty.. But not recommended of course, I was in test mode only..... I did take that big bull with a 350 ESP Raptor that was tipped, and he was hit very hard and was down on the spot..... I was only running it at 2700 and change......



There is just so much you can do with these .500s and so many good bullets. As for bullets, we have far far more good bullets in .500 now than .510......... And more good cartridges in which to utilize those bullets!

Michael

quote:

...I used this in Australia last year with Paul on some of those buffalo....

I looked at that culling hunt at Australia, seems to be an inexpensive way to field test a new gun. What did you do about ammo? Their web site recommends at least 200 rounds. At approximately 600 or so grains a cartridge, that comes to about 128 rounds as far as the airplane ammo allowance of 5kg. If I were to take a backup gun of a different caliber then I would be even more short of required quantities.

Tanks...

I think I carried about 60 rounds of 416 B&M, and 60 or so of 500 MDM, then I shot up all of Paul's 500 MDM ammo.

HEH HEH



I only shot a few buffalo........... :hillbilly:

Secret to carry ammo....... Take your wife and kids.... It says 5kg per PASSENGER, not 5kg per Shooter! Momma is always having to give up her shampoo for BULLETS..........

M

quote:

Originally posted by michael458:
...
Secret to carry ammo....... Take your wife and kids.... It says 5kg per PASSENGER, not 5kg per Shooter! Momma is always having to give up her shampoo for BULLETS..........

...

Well, I guess I could invite all of my ex-wives, then I'd have enough ammo for the year

On a serious note, I already asked my girlfriend about how she felt about going to Australia again. I am sure she could sit at a resort somewhere and enjoy herself while I am in the bush. .

Is that barely evident shoulder ever an issue?

Dog.....

Answer, No, never an issue. I have chamber gages here, and while I did not take a big hammer to it, one cannot tap the case further than the ghost shoulder, it provides a positive stop. But beyond that, and to me of far greater import, is that I will only allow these cartridges to be done on control feed guns, as I am a firm believer in the extractor having more to do with controlling headspace than other factors. That cartridge cannot go into the chamber any further than the extractor will allow it to go.......... The 50 B&M is the same RUM case, has absolutely zero shoulder on it, while some might state the case that it can headspace on the mouth, which is very true, it also cannot go into the chamber any further than the extractor will allow it to go. To prove this point beyond shadow of a doubt, I have taken my 50 B&M Super Short, a 1.65 inch WSM case, which fits nicely in the 50 B&M Chamber... 2.25 inch RUM case. Now this is .6 inches shorter than the mouth of the chamber, and the only thing working is the extractor.... 100 rounds... 100%..... Accuracy was horrible however, lots of bullet jump there.......

Short and long of it......... Short many 1000s on top of 1000s of rounds fired, zero issues.........

Michael

quote:

I could invite all of my ex-wives, then I'd have enough ammo for the year

Tanks.....

I can see quite a bit of trouble with this, I think we can find a better way........... HEH.......

Speaking of better ways to do things, one thing about any of the B&Ms, MDM included, I am always looking for a "better way"....... From bullets to powder to anything else concerning the cartridges/rifles. While there is not much of a way to improve now our bullet tech, with both CEB and North Fork, there are always new powders, and such coming online to take a look at. Not to mention blending powders which I have delve into with the 500 MDM with some success. One powder I looked at very seriously is V-N530.... Unfortunately I only had 1 lb of this, so I could not complete the study, but did get to the point that I am excited about more research with this powder. And have been looking for more of it weekly now for a few months, none to be found. IMR 8208 is currently our best all around powder right now, and will most certainly do for the future, but to give you an idea with the 500 #13 Solid and 95/IMR 8208 gives us 2370 fps at 61000 PSI. I have used 97-98 to push that over 2400, but at max pressures of 64000-65000. The recent test of 92/V-530 gave us 2340 fps at only 54171 PSI, with lots of room to grow, I ran out, but my notes tell me the next test is 94/V-N530.......... I think there is potential here to either equal velocity with IMR 8208 or Exceed it, at less pressure..... Always a good thing...... So the research here never ends, and from time to time even old data is updated and checked again......... Just FYI......

Michael

quote:

Originally posted by michael458:
...One powder I looked at very seriously is V-N530.... I am excited about more research with this powder. And have been looking for more of it weekly now for a few months, none to be found. IMR 8208 is currently our best all around powder right now...

Powder situation seems to be tough all around. I was lucky enough to score 16 pounds of IMR8208 from one vendor that has been trickling it in limited quantities, though it took me 3 separate transactions on three separate days to buy that amount, and of course hazmat fees X 3 . So, now just need to decide on bullets before the gun gets ready.

As far as V-N530 goes no one seems to have it anywhere. If I find any, I'll make sure it gets drop shipped to you for the research .

quote:

Originally posted by michael458:
Dog.....

Answer, No, never an issue. I have chamber gages here, and while I did not take a big hammer to it, one cannot tap the case further than the ghost shoulder, it provides a positive stop. But beyond that, and to me of far greater import, is that I will only allow these cartridges to be done on control feed guns, as I am a firm believer in the extractor having more to do with controlling headspace than other factors. That cartridge cannot go into the chamber any further than the extractor will allow it to go.......... The 50 B&M is the same RUM case, has absolutely zero shoulder on it, while some might state the case that it can headspace on the mouth, which is very true, it also cannot go into the chamber any further than the extractor will allow it to go. To prove this point beyond shadow of a doubt, I have taken my 50 B&M Super Short, a 1.65 inch WSM case, which fits nicely in the 50 B&M Chamber... 2.25 inch RUM case. Now this is .6 inches shorter than the mouth of the chamber, and the only thing working is the extractor.... 100 rounds... 100%..... Accuracy was horrible however, lots of bullet jump there.......

Short and long of it......... Short many 1000s on top of 1000s of rounds fired, zero issues.........

Michael

How about if a cartridge gets ahead of the extractor? My concern is that a cartridge would be driven ahead by the bolt before the extractor could jump the rim and tie everything up. Not to say that it will, or has, but that was my concern.

I know that theoretically CRF actions should be fed from the magazine, but I won't own one that absolutely has to be or needs a extractor squeeze to jump the one in the pipe.

Seems like the right place/guy for the question.

Dog.....

90% of my experience is with Winchester M70 Control Feed guns. I have never experienced the cartridge getting ahead of the bolt and not being locked in the extractor....... However, one can take any of these cartridges and drop one in the barrel, then drop the bolt on them and let the extractor snap over the cartridge, which I have done a good bit. On proper formed brass, this cannot be an issue, or it never has been. I Have taken brass that is ONLY FORMED, not actually fire formed to the chamber, and had the extractor not snap over on the first try, but this is because the brass was not formed, or because the extractor just did not jump over for some reason.... Even the 50 B&M that has no shoulder at all you can drop one in the tube and close the bolt, extractor snapping over, as it stops on the mouth in the chamber...... Other rifles I really can't speak for with any reasonable experience..... Only the Winchesters.....


Tanks...
Yep, if you run across any V-N530 keep me posted... This powder is very very promising....... Package leaving today headed in your direction.....

M

IMR 8208 XBR

I heartily recommend this powder, though I have not laid hands on any of it yet.

It is made by ADI in Australia where they call it Benchmark 8208.
Same thermal stability as the Hodgdon Extreme line of powders they also make.
Hodgdon BENCHMARK Extreme is called Benchmark No. 2 as made by ADI.
ADI also has a Benchmark No.1, fastest of the three ADI Benchmark powders.

IMR 8208 XBR is the slowest of these three ADI Benchmark powders, but it is still pretty fast,
closer to IMR 3031 than to IMR 4895.


I used to be a "temperature sensitive" kind of guy who demanded that his powders not be "temperature sensitive."
But I hate that "sensitive" label, so now I call myself "independent."
My powders must have "BALLISTIC THERMAL INDEPENDENCE."
I learned that terminology at the ADI web site.
Bye-bye sensitive guy.

BTW, my 400 Whelen-B now headspaces on the shoulder, case mouth, and extractor.
At least one of those is doing the job, fail safe.
That is a trick I learmed from Doc M at MIB.

RIP and all....

IMR 8208 is almost a miracle powder for us big bore guys.... In recent studies with 458 Winchester and 458 Lott it is right at the top as best powder for velocity/pressures. Excellent in 500 MDM, and the new 500 B&M as well... I found it very good in 458 and 416 B&M as well, maybe not the top powder, but most certainly good......

quote:

Originally posted by RIP:
IMR 8208 XBR

I heartily recommend this powder, though I have not laid hands on any of it yet.

...

In case you are interested...

http://www.recobstargetshop.com/browse.cfm/2,69.html

They have them at the moment in 1 pound quantities, though you are limited to 4 pounds per day.

Hey, if it works it works. My interest is only in the M70 in this case anyway, and a 1/2 inch M70 does have a definite appeal.

quote:

Originally posted by tanks:
In case you are interested...

http://www.recobstargetshop.com/browse.cfm/2,69.html

They have them at the moment in 1 pound quantities, though you are limited to 4 pounds per day.

So this is what it has come to, paying hazmat fees.

Doc M,

Please, how about telling us this about the 500 MDM:

1. The minimum chamber length on the reamer spec (from boltface/base to neck-2/casemouth of chamber), and

2. The maximum brass length spec for the cartridge case, and how short to let it be in practice: Brass length max and min.

Surely this is not still top secret proprietary information?
Do you not wish to continue your reputation of selfless service to humanity by revealing this information?

RIP...

No man, no big secrets here......... You just ask HARD QUESTIONS... LOL.....


#1..... I DON"T KNOW! HEH... Not sure if I even have the reamer spec or drawing somewhere, this I will have to search. I had them at one time, some years ago, but have changed computers since then, but still should be somewhere on the externals.... I will have a look.........

#2..... I can tell you this, easy one, 2.8 inches max case length, I normally trim to 2.790-2.795 or so. Minimum... Really can't say, I can say that when there was NO 375RUM available, and I had 338 RUM, I made some 500 MDM out of the 338 RUM and that come in at 2.760 and worked great. I have not had a reason to be any shorter than that.

I sincerely hope this somewhat maintains my reputation?

M

Ron sounds like some of the 'short lengths' you guys have been using with your 400 Whelen cartridges.

Also guess it adds fuel to the benefit of the full bite CRF extractor vs the little hook PF extractor...

Jim,
Yep, Doc M does seem to be leading us away from headspacing on case mouth for the .500 MDM.
But the only way to put this to rest is to tell us more.
Of course the entire chamber reamer drawing for the .500 MDM would be most informative,
just to show he does not have some other trick with the tolerances up his sleeve.
And I should hope he does not redact any of the measurements with a black marker,
like a politician responding to a congressional subpoena, evoking executive privilege, etc. ...

This is ground-breaking NON-CONVENTIONAL stuff!
After nearly a century of non-believers' belly-aching about the insufficiency of the 400 Whelen or other minimal shoulders,
this demands full elucidation for the enlightenment of all humanity.
Almost as good as cold fusion, but true!

Ron,

I keep writing and then delegating a multi-paragraph response so I'll try again.

Not going to happen in the near future...

There finally finished one...

Jim,
No reverse engineering intended, just understanding desired.
I won't hold my breath. That is a bad thing to do with a broken rib.
(Whining for sympathy now.)

quote:

This is ground-breaking NON-CONVENTIONAL stuff!After nearly a century of non-believers' belly-aching about the insufficiency of the 400 Whelen or other minimal shoulders,this demands full elucidation for the enlightenment of all humanity.

This is very true. Though we need to remember the quality of brass delivered as a whole today in only replicated by special brass runs of yore.

Oh yes - here's some sympathy thrown your way.

quote:

Originally posted by RIP:
Jim,
No reverse engineering intended, just understanding desired.
I won't hold my breath. That is a bad thing to do with a broken rib.
(Whining for sympathy now.)

Remember to breath deeply, no matter how much it hurts. No use having broken ribs and pneumonia. Bin dere, dun dat.

You guys are such a bad influence on me! I am getting more and more intrigued with this cartridge and thinking of eventually having a rifle built around it. I'd love to know the ballpark for a full custom built as you gents have- I actually purchased a similar rifle from Michael's collection in .458 Lott that would be exactly how I'd spec the MDM.

Are you all fireforming RUM brass, or can you purchase brass with proper headstamps? Certainly makes for an interesting package!

-John

quote:

Originally posted by John Galt:
You guys are such a bad influence on me! I am getting more and more intrigued with this cartridge and thinking of eventually having a rifle built around it. I'd love to know the ballpark for a full custom built as you gents have- I actually purchased a similar rifle from Michael's collection in .458 Lott that would be exactly how I'd spec the MDM.

Are you all fireforming RUM brass, or can you purchase brass with proper headstamps? Certainly makes for an interesting package!

-John

John, I feel your "pain".

I have both SSK-built .458 Lott and .500 MDM, almost identical with the only major difference between them being the length of barrels, the MDM is 20" long, the Lott at 22".

Both handle and shoot extremely well and are a joy and pleasure, at 8.5lbs, to carry long distances for extended periods of time.
Both hammer buff into submission with regular monotony, (when loaded with good bullets !!!).

Do you "need" both ?

Yes,...... yes you DO!

Why, I don't know, I can't remember but I do remember that when I ask Mike that question he responds,
"every home should have at LEAST one .50 cal in the rack".

It works for me, and i'm confident it will work for you.

And in response to your other question, I am using Mike's corn-meal recepi for forming cases, which works quite well, but am also fortunate to have had a very special friend custom make me a series of forming dies (which I haven't used yet).

I can safely assure you that should you have opportunity to do some buffalo, and up, hunting the MDM is an exceptional performer.

quote:

Are you all fireforming RUM brass, or can you purchase brass with proper headstamps?

John

I have really had a pain of a time with getting proper headstamped brass, that will actually work and hold pressure, especially in the 500 MDM..... I posted this on the B&M thread just a couple of days ago concerning just that subject.............

quote:

Oh, and as a Side NOTE concerning Horneber........ I believe it was October of 2011 as I recall that I decided to try Horneber one more time. After some weeks of email and confirm that I want 65000 PSI brass, Dieter Horneber and I came to terms with 2000 pieces of B&M brass, not formed, but basic straight....... I sent a tad over $4000.00 to his account........ I was told February of 2012 I would have brass.............

Well, its now April 2014 and I have no F**K**G Brass, I tried for a year to contact, no luck there either......... Needless to say I am not a satisfied customer........

Michael

Cappy.......

Yes, this brass issue has been really a pain. After the Horneber incident I really have become discouraged with the whole thing. There is Captech which I contacted early when they were starting back up, but got wind of some of their requirements and went beyond what I was willing to expense from personal funds..... The best and simple solution for any future issues is to mark the barrels.... Such as... 500MDM/375RUM or 458 B&M/300RUM, or 50 B&M Super Short/300WSM in this manner all bases are covered, and use the brass the cartridge was designed around without issue, and reach full potential.

I actually got the contact info for Bertram from Ed, sent email, never got a reply........

500 MDM was designed around the RUM case, at 2.8 inches.... So far I have not been able to get any of the other brass to meet those specs 100%...... Thus, I have my barrels, and recommend all others do the same marked 500 MDM/375RUM, covers all bases then, if anyone were to ever check such a thing......... People who might look would not know the difference between 500 and 375 anyway...... After many trips to many different countries I have never had anyone look at that.

M

Thanks to Tanks, we have a 8# container of H-4895 on the way.... A few months ago, I was testing H-4895 in the 500 B&M, along with what little V-N530 I had left.... H-4895 proved to be equal to V-N530 in the 500 B&M case. I was not able to do any tests in the 500 MDM with H-4895. But did in what was left of 1# of V-N530 which looked like might be the miracle powder in 500 MDM.... H-4895 might do exactly the same in 500 MDM as well, with 8#s of it, this will be enough to run a complete set of pressures in both 500 MDM and 500 B&M with all suitable bullets..... I have very high expectations for this. And at any rate, during hard times of getting powder and components, it never hurts to have yet another powder we can use in our cartridges.......... Currently we have good solid data on the following powders and bullets larger than 450 grs.......... All of which would do dandy in the field, buffalo, elephant, hippo..........

IMR 8208, Benchmark, RL 15, IMR 4064, H-322, V-N530, V-N140, IMR 4320, Varget, blend of 60% RL 15 + 40% RL 7.......

Next, more data V-N530 when we can get some, and now H-4895....... Research continues.............

Michael

Well, just pulled the trigger on a 5 day NM black bear hunt starting on August 16.

Assuming it is ready by then I will be using 500 MDM with 335gr BBW#13s for this. I think it is enough gun

It should fit well for a hound hunt with plenty of stalking/chasing.

Must be a B-I-G Black Bear :-)

Well choices are .22LR Annie, 375H&H with a 24" barrel, or a 20" barrel MDM in the forest.

I also don't have to load the cartridge at max velocities either.

quote:

I also don't have to load the cartridge at max velocities either.

One of the most wonderful things about a Big Bore cartridge/Rifle... You can ALWAYS load them down, but you can't take a medium and load it up to a Big Bore......

I bet we can find some loads with that 335 down in the 2300 fps range, shoot like a 22 hit like big hammer on bear run with dogs..........

They tell me that the H-4198 has arrived....... I will be starting load data on that very soon, along with updating some 50 B&M that is in progress, and getting ready for Zimbabwe in June myself as well....Lots to do between now and mid June......... And I think Biebs is still on schedule best of my knowledge, and maybe Tanks very soon after I return 1st week of July........ Have it ready for the bear.........

M

Michael,
I'm getting ready to send you a Remington Ultra Mag rifle and I want it converted to the caliber you decide will be good, no Great for Dangerous Game. Let me know when it's done.

quote:

Originally posted by michael458:
One of the most wonderful things about a Big Bore cartridge/Rifle... You can ALWAYS load them down, but you can't take a medium and load it up to a Big Bore......

+1