The Accurate Reloading Forums
Pressure signs with different brass
23 June 2020, 01:52
impala#03Pressure signs with different brass
I am working up load for a Ruger #1, 275 Rigby. 130 gr. CEB Raptor, 42 gr. IMR 4064. Velocity +- 2900 fps. PPU brass very hard extraction, Hornady brass, same velocity, normal extraction. Both are once fired cases out of the same rifle being tested. No I did not weigh the brass yet, but think this may have something to do with the problem. I have never experienced this before. Information I obtained from CEB indicated up to 44gr IMR4064 to be safe. Guess it pays to test, test, and test some more. Yes I am an experienced hand loader, 50+ years, and I don't hotrod my loads. Anybody else experience this?
23 June 2020, 17:12
victor1050I loaded PPU brass once for a 300 win mag. They shot well but the cases held about 3-4 grains of water less than my norma brass and I had to adjust the loads down to avoid pressure signs (hard extraction, ejector wipe). You are probably seeing a similar issue. I would take 5-10 cases and check the capacity with water.
23 June 2020, 19:04
tsturmquote:
Originally posted by impala#03:
I am working up load for a Ruger #1, 275 Rigby. 130 gr. CEB Raptor, 42 gr. IMR 4064. Velocity +- 2900 fps. PPU brass very hard extraction, Hornady brass, same velocity, normal extraction. Both are once fired cases out of the same rifle being tested. No I did not weigh the brass yet, but think this may have something to do with the problem. I have never experienced this before. Information I obtained from CEB indicated up to 44gr IMR4064 to be safe. Guess it pays to test, test, and test some more. Yes I am an experienced hand loader, 50+ years, and I don't hotrod my loads. Anybody else experience this?
I have used lots of ppu brass in 223 & 308 it has less case capacity than the fed., rem. & win. I was used to. I just dropped favorite loads a couple grains.
23 June 2020, 19:58
impala#03That's what I thought. Thanks for the comments.
Yes that is one of the reloader's basic pieces of required knowledge; weigh your brass first, compared to what the book used, or what you used before; then you will know how it will react to the same load. Heavy brass has less capacity; as you now know. Since the outside is the same, the inside must be different.
Softness of the brass can have negative effect too.
Some of my friends have 50 years of reloading experience, but upon watching them I found that they actually have one year's experience repeated 50 times, so when something new comes along like using a different make of brass or anything out of the very ordinary, they hit a snag. Or blow primers, like one of my friends does; Or burn out the firing pin hole. Or blow up a Swede 96....
I learned to stand 15 feet away from them at the range.
same velocity.
same powder amount [gas volume available]
less pressure?
I'm not a math major by any means so someone is gonna have to splain this to me.
how can you push on something less hard and get it up to the same speed using the same friction coefficient.
13 July 2020, 10:29
sambarman338This subject interests me greatly and I would like someone to explain the seeming dichotomy between case capacity as a factor in pressure and case thickness as a factor in containing pressure.
As I mentioned in the Lever-action forum, I found great differences between the weight of .45-70 Starline and PPU brass, yet wonder, assuming the limited capacity of the former adds to pressure, does its increased mass indicate thicker walls that might enhance its ability to cope with that pressure, esp. if I restore capacity by seating bullets farther out in my rifle's extended throat.
Though flattened primers appear even with my milder reloads, I also notice a lot of soot extending back along the case, something I've been led to believe indicates low pressure.
When I was trying to get a little more steam into my 375 Winchester ('Big-Bore') a buddy suggested shortening .38-55 cases because the brass was thinner and would hold more powder. This also caused me to scratch my head because I'd heard that the thicker brass in the 375 Win was to allow it to work at higher pressures.
13 July 2020, 18:13
jeffeossorule of thumb - change
ANYTHING, back the loads off 10% and work up ...
but, heck, i find that the middle load in the book does just fine (there are exceptions) and if i need 300 fps more than that, i get to build another gun!
mixing brass CAN be done .. mild loads and practice ammo .. basically blasting ammo .. but i don't do it in anything other than 9mm
14 July 2020, 15:13
Peter Connanquote:
Originally posted by sambarman338:
This subject interests me greatly and I would like someone to explain the seeming dichotomy between case capacity as a factor in pressure and case thickness as a factor in containing pressure.
I am merely theorising here, but I suspect that a flattened primer has more to do with the pressure in the primer than the strength of the cartridge case itself. The primer walls are much thinner than the case walls, so the primer will balloon and stretch, and then get knocked flat before the case does so.
Increased case wall thicknesses do substantially reduce the maximum stress in the case walls at the point where head separation occurs, but in high-pressure modern calibers the maximum allowable pressure is generally equal to the maximum yield stress of cartridge brass, and since the cross-sectional area of the case wall is less than cross-sectional area of the powder column, the maximum stress in the case wall will significantly exceed the yield stress. Thus, the reduction in maximum stress will result in the cases lasting longer, but it does not result in the weapon as a whole being able to handle higher pressures, as that is controlled by the steel and not the brass.
14 July 2020, 17:52
Mike_DettorreI use Hornady brass for my 308, 7mm-08, & 30-06.
I have found Hornady brass consistently weighs less than other brass.
For example, the majority of my Hornady 308 brass usually weighs 153 +/- 1 grain. But note, every once in awhile I find a hornady 308 case that weighs 167 grains and some as low as 151.
FC brass in 308 consistently weighs around 177 grains.
Another example, I find Hornday 30-06 brass to normally way around 172 grains where Win brass weighs around 186 grains.
Mike
What I have learned on AR, since 2001:
1. The proper answer to: Where is the best place in town to get a steak dinner? is…You should go to Mel's Diner and get the fried chicken.
2. Big game animals can tell the difference between .015 of an inch in diameter, 15 grains of bullet weight, and 150 fps.
3. There is a difference in the performance of two identical projectiles launched at the same velocity if they came from different cartridges.
4. While a double rifle is the perfect DGR, every 375HH bolt gun needs to be modified to carry at least 5 down.
5. While a floor plate and detachable box magazine both use a mechanical latch, only the floor plate latch is reliable. Disregard the fact that every modern military rifle uses a detachable box magazine.
6. The Remington 700 is unreliable regardless of the fact it is the basis of the USMC M40 sniper rifle for 40+ years with no changes to the receiver or extractor and is the choice of more military and law enforcement sniper units than any other rifle.
7. PF actions are not suitable for a DGR and it is irrelevant that the M1, M14, M16, & AK47 which were designed for hunting men that can shoot back are all PF actions.
8. 95 deg F in Africa is different than 95 deg F in TX or CA and that is why you must worry about ammunition temperature in Africa (even though most safaris take place in winter) but not in TX or in CA.
9. The size of a ding in a gun's finish doesn't matter, what matters is whether it’s a safe ding or not.
10. 1 in a row is a trend, 2 in a row is statistically significant, and 3 in a row is an irrefutable fact.
11. Never buy a WSM or RCM cartridge for a safari rifle or your go to rifle in the USA because if they lose your ammo you can't find replacement ammo but don't worry 280 Rem, 338-06, 35 Whelen, and all Weatherby cartridges abound in Africa and back country stores.
12. A well hit animal can run 75 yds. in the open and suddenly drop with no initial blood trail, but the one I shot from 200 yds. away that ran 10 yds. and disappeared into a thicket and was not found was lost because the bullet penciled thru. I am 100% certain of this even though I have no physical evidence.
13. A 300 Win Mag is a 500 yard elk cartridge but a 308 Win is not a 300 yard elk cartridge even though the same bullet is travelling at the same velocity at those respective distances.
The primer is always the weak link; thicker brass might make it last longer but won't let you increase pressure; you still have the same primer.
Lesson in using high pressure; one of my jobs was managing Tank Ammunition. The M256 Cannon, 120mm, smoothbore, uses a fairly conventional dropping block breech. But the ammo operates at close to 100K psi to get the SABOT round at around 5000 fps. How? We use a steel cartridge case (only about 8 inches long with a rubber obturator), and an electric, screwed in primer. That's how. If we had that in rifles, we could do great things.
Probably best we don't as the primer is sort of a check valve to keep guys from blowing stuff up.
14 July 2020, 21:03
Peter ConnanThat is very interesting dpcd
Is that the gun in the Abrams?
The M256, a Rheinmetall design, is in the M1A1 and A2 Abrams; the M1 Abrams and M60 series used the 105mm, brass or steel case. Still a very capable round.
15 July 2020, 00:58
AtkinsonPPU and Rem are the thickest brass, load a grain less than Win for example, thicker brass has combustion in a smaller container, so pressure is slightly more in PPU and Remington but for the same muzzle velocity as the thinner brass with the larger container..
All that said I load the same load in my PPU brass ( a favorite btw) as I do in my WW brass and have never had the inferred problems, all things being equal, have for over 60 plus years.
However there are a number of things that can cause your problem, and Im assuming you know that after 50 years of reloading. 44 grs. of IMR-4064 could by some be hotrodding, my suggestion is change powder to H-414 as 4064 is a powder that spikes from time to time..and 414 will get you more velocity with several grs. over max and still milder pressures..
Ray Atkinson
Atkinson Hunting Adventures
10 Ward Lane,
Filer, Idaho, 83328
208-731-4120
rayatkinsonhunting@gmail.com
15 July 2020, 10:22
Peter Connanquote:
Originally posted by dpcd:
The M256, a Rheinmetall design, is in the M1A1 and A2 Abrams; the M1 Abrams and M60 series used the 105mm, brass or steel case. Still a very capable round.
Thank you.
Never knew those big guns run at such high pressures.
I wonder if they ever will get liquid propellant to work properly (I guess the only real problem is obturation, with injection technology as good as it is now)? That has the potential to make a big impact on tank design.
15 July 2020, 12:19
sambarman338Thanks for your thoughts, guys.
My weighing those .45-70 cases, Mike, actually found the Hornady cases a fair bit heavier than the PPU ones, even though Hornady's were much shorter.
From Peter and dpcd I glean that thick case walls may raise the pressure but not give protection from it, so maybe my mate's advice on the .38-55 brass had some merits - but only for a load or two - as long as the primers don't flatten.
So what to do? I will seat my .45-70 bullets out a bit, hoping to at least to lower pressures a little. I haven't noticed much difference so far, but will keep at it.
16 July 2020, 09:09
bentaframeI load for two wildcats based on the 30-30 case. I found Hornady and starline too soft when fireforming. 50-75 % failure rate with new brass. R-P, Winchester and Federal brass worked fine. The Federal had less case capacity and approached pressure signs quicker.
25 July 2020, 00:45
AtkinsonTo start with you work up your loads using X components, if you decide to change, brass, primer, and to a lesser degree bullets, its time to start over and work up that load to your required specs...
I know a lot of folks don't jump on that as its too much trouble and Im as guilty as the next guy as it just hasn't been necessary in my case..I might end up with a blown primer or a pressure happening, but never has been enough to blow up anything and generally I just cut back a grain or two and continue my shooting...Its worked for near 70 years, and most of my mistakes and happenings took place when I started reloading at age 12, those were exciting days especially since I was the only reloading in the Texas Big Bend I think! and fearless I might add.
flying by the seat of my pants, there wasn't any information available or a store within a 150 miles, but damn the hunting was good both in Mexico and Texas.
I used a tire and a string blowing up rifles, mostly cheap stuff and stuff out of lakes and we bought Springfields for $7.00 NRA, and colt 1911 for $14. and milurp Mausers were a dime a dozen..results?, its damn hard to blow up most rifles and some like the Jap Arisaka flat won't give,not even with a case full of bullseye, but my goodness,its one ugly gun..
Not suggesting anyone practice these things just passing it on for your knowledge if there is any to be had..for instance a 98 mauser with a case full of bullseye will puff up like a balloon split perhaps, but will not fracture, a mod. 70 or 54 will come apart like a handgranade slinging sharpnell in all directins but it takes all the hot powder you can tamp in the case, its truly a strong action..Just some food for thought..walk softly in the endeavor. an today all the information is there to be had on the internet and dozens of books..
Ray Atkinson
Atkinson Hunting Adventures
10 Ward Lane,
Filer, Idaho, 83328
208-731-4120
rayatkinsonhunting@gmail.com
25 July 2020, 11:04
sambarman338That was a great little story, Ray, hopefully plucked from your upcoming book
25 July 2020, 21:51
4sixteenLoad my No.1 7.62x39 pretty warm using new PPU brass no issues (example 130gr at 2700 fps). Although 7.62x39 brass is robust thick webbed/walled. Rigid action never experienced hard extraction loading any of my No.1's with stoked up loads. Slightly less case volume shouldn't make that much difference? My guess maybe your brass is from a production run with abnormally low yield strength.
27 July 2020, 10:39
eagle27Reading pressure is all about comparison in your gun. Doesn't matter what happens in anyone else's gun using same cases, primer, powder and bullets it's all about changes in your gun.
Primers do give an indication of pressure, in a particular gun. I can guarantee that if you work up charges in your gun, with same case, same primer, same bullet your primers will start to flatten to a point where bolt lift will get sticky, maybe before or after other signs such as plunger ejector wipe on the case head, incipient case head separation etc. ALL of these indicate climbing pressure levels to the point of approaching dangerous. Doesn't matter didley squat what the book says or someone else's gun does it is what is happening in your gun. Case capacity and bullet seating depth/freebore all influence pressure.
However in some instances and in the absence of any other pressure signs, very flattened primers may still be a safe load in your gun. Below is the primer of 7x61 S&H Norma factory loads fired in my Schultz and Larsen rifle. Many would be frightened off seeing such flattened primers but the S&L rifles were supposedly tested to over 100,000 psi pressure without any ill effect.
I wouldn't recommend handloading to this level but the once fired cases last well for reloading, sized to seat on the shoulder and not the belt.
27 July 2020, 19:41
AtkinsonWhat comes to mind IMO on this thread is the poster is shooting a Ruger #1, and that action is strong enough to handle his problems with ease, so whats causing the pressure? or at least the sticky case?? I think a chamber cast might be the answer, and the gun MIGHT be a chamber cut with a worn out reamer giving it a ultra tight bench rest grab..Hard to say! If that's the case a recut chamber may be in order, or a good polishing or just cut two grs. with PPU brass and get the same velocity, run these loads over the chronograph, that's what I would do...I know on my m-70 pre 64 I use two grs. less powder with Remington brass and get the same velocity as two grs more in WW brass..and POI is the same, but I use the WW load with PPU brass and no problem, thus my belief that rifles are an inity unto themselves..Just some thoughts on the subject, hard to say without gun in hand.
Ray Atkinson
Atkinson Hunting Adventures
10 Ward Lane,
Filer, Idaho, 83328
208-731-4120
rayatkinsonhunting@gmail.com
31 July 2020, 20:03
243winxbAnnealing may make the difference?
From Olin Brass- modulus of elasticity- Cartridge Brass-
Material is 70 copper/30 zinc with trace amounts of lead & iron , called C26000. Material starts to yield at 15,000 PSI when soft (annealed), and 63,000 PSI when hard.
Material yields, but continues to get stronger up to 47,000 PSI when soft, and 76,000 PSI
when work hardened. Modulus of Elasticity is 16,000,000 PSI. This means to pull a 1.000 inch long strip to 1.001 inch long induces a 16,000 PSI stress.
So if you pull a 1.000 inch strip to 1.005 inch long, you get about 76,000 PSI, which is the max obtainable.
When the neck and shoulder are annealed, the part near the case head is heated to maybe 400F. This will stress relieve the brass and allow it to flow more easy.
It was found that some Win 223 brass that skipped 1 anneal, caused case head separations in the brass. When the extra anneal was *done, the separations stopped. Gov. Info.
10 August 2020, 19:39
SSI01quote:
Originally posted by Peter Connan:
quote:
Originally posted by dpcd:
The M256, a Rheinmetall design, is in the M1A1 and A2 Abrams; the M1 Abrams and M60 series used the 105mm, brass or steel case. Still a very capable round.
Thank you.
Never knew those big guns run at such high pressures.
I wonder if they ever will get liquid propellant to work properly (I guess the only real problem is obturation, with injection technology as good as it is now)? That has the potential to make a big impact on tank design.
Saw a short video on an experimental self-propelled gun using liquid propellant that had a phenomenal rate of fire, I think it was a 155mm - basically stuff the shell into the chamber, close and lock it, shoot a whiff of the correct propellant into the chamber behind the shell and ignite it, and VOILA! Had the added benefit of no powder/bag residue glowing in the chamber after firing. Complete combustion every time. Higher rate of fire, smaller crew. Practically no muzzle flash, either. Don't know why it was never adopted.
18 August 2020, 21:48
AtkinsonAnnealing is never a mistake, if one annealed every firing brass would last forever..Id rather shoot a case 5 or 6 times, toss the bunch and buy another 100 or so..I don't shoot enough these days to justify annealing, although I have an annealer that a fine gent on AR gave me and it sure is handy with my .348 cases that are hard to find and if you do they cost an arm and a leg..so I anneal them every couple of loads...that's when an annealer comes in handy, its a must.
Ray Atkinson
Atkinson Hunting Adventures
10 Ward Lane,
Filer, Idaho, 83328
208-731-4120
rayatkinsonhunting@gmail.com
23 August 2020, 19:16
F. Guffeyquote:
When the neck and shoulder are annealed, the part near the case head is heated to maybe 400F. This will stress relieve the brass and allow it to flow more easy.
How is that possible? There has to be more than one answer if there are two different methods for annealing.
F. Guffey
23 August 2020, 20:23
243winxbMr. Guffey. Search here.
https://discover.dtic.mil/The Win 223 ammo worked fine in our M16. But when fired in a foreign-made rifle , with different action timing, there were case separations.
One more annealing step in the manufacturing process stopped the case head separations.
24 August 2020, 04:32
F. Guffeyquote:
When the neck and shoulder are annealed, the part near the case head is heated to maybe 400F.
I did not think you would understand the question; if a reloader was using water in a pan how is it possible he could heat the case head to 400 Degree Fahrenheit. According to you the water would not make contact with the case.
I have a pile of brass that was supposed to have gone through the 'one less annealing step'. There was a recall, I did not find out about the recall until I had fired 60 casers three times. I thought the brass was magnificent brass; it meant nothing to me so I added the cases to the drawer of collectable brass.
Case head separation and head space: This stuff does not lock me up, if the case is going to suffer case head separation I can determine if it is possible.
F. Guffey
24 August 2020, 11:36
NakihunterGraeme Wright's book on shooting the British double rifle has info on annealing brass. He says you just need to old the rim in your fingers and heat the neck. Drop it on a cloth when too hot to hold.
I do that for my 416 Rigby & 470 NE after 2 firings.
"When the wind stops....start rowing. When the wind starts, get the sail up quick."
24 August 2020, 19:28
F. Guffeyquote:
Graeme Wright's book on shooting the British double rifle has info on annealing brass.
"Shooting the British double" a case head heated to 400 degree will fry bacon.
Many years ago I suggested reloaders do some research and then decide on the rules for annealing. I did not expect much, I did not get much so I used my list. Mr. Wright sounds like he would have been someone that was interesting to talk to.
F. Guffey
