Brass longevity study!

[drmarkwg]

I just completed a study on brass longevity and posted it on my blog at headstampfinebrass.blogspot.com. I have followed many of the threads on the site for years and would appreciate feedback on this study which looks at how many times 9mm brass can safely be reloaded. Thanks

[mjm]

Interesting. I appreciate the good work. Part of the blog was blocked by my employer, so I might have missed something. Did you post the results of all tested manufacturers?

If I read correctly, you used two cartridge samples. I encourage you to increase the sample size. This helps make the statistical analysis much more sound.

Again, good work!

[drmarkwg]

Thank you, larger sample size is planned for the next bit of research. All manufacturers were included in the statistics. I have an Excel spread sheet and graph with the raw data but was unable to post it in the blog. Technologically challenged. I have since figured it out and the chart is now on the blog. Your input is greatly appreciated.

[Shane Tuttle]

Would you be so kind and provide some exerpts or a general overview of your blog? That way, others can see a sampling of your studies and provide a little more enticement to check your blog out...

[drmarkwg]

Sure, here is the summary of the experiment.
Summary: The 50 cases produced 1807 rounds of ammunition which functioned flawlessly through the weapon. The average number of firings before failure for the entire experimental group was 34.75. One case was fired 68 times prior to failure. The data gathered in this study indicate that the Identification of brass which is unsafe to reload is accomplished by a simple visual examination of the brass to be reloaded. Any cracks or splits at or below the case mouth should be removed from service and permanently discarded. Brass failures in the 9mm were consistently noted to be case splits at or just below the case mouth. No failures of the brass were noted during firing. Failures were noted during a visual examination of the case prior to reloading. There were no potential safety events, those leading to harm to the weapon or shooter, during the entire experiment. Careful visual examination of the brass case to be reloaded, which revealed no grossly abnormal appearance, nor splits or defects at or below the case mouth, in each case resulted in normal and safe firing of the reloaded cartridge.The brand of brass with the greatest longevity was A-Merc 9mm RH. With an average number of firings before failure (ANBF) of 52. These cases were reloaded without any malfunction or detectable failure for an average of 52 times. The shortest longevity was the Federal FC 9mm LUGER with an ANBF of 11.5.

Thanks for the input.

[Sevens]

UGH!
Simple process of elimination gives us the ultimate in any discussion.

Here on planet Earth, the ultimate horrible yet boxer primed and technically reloadable brass is A-Merc. And it's a no-contest victory with nobody else even close.

[mrawesome22]

AMERC troll? Only 3 postings and touting their brass when thousands of other posts lean in the entire other direction...

I smell fish...

[armoredman]

A-Merc? That brass is terrible, yuck.

[Sevens]

Oh, I doubt he's a troll... I mean, I didn't check the blog. I find it a bit annoying that we have thousands of conversations here daily but the OP doesn't want to take part in that and would instead have conversation on his site and hopes to direct our traffic there, but as for his experiment -- you'd have to be off your rocker to put that much time and energy in to any project where the result is specifically geared to trump up A-Merc component brass. <my-sides-are-splitting-smiley>

[dunerjeff]

Its interesting but with only 50 case and like 20 different h/s that isn't enough of a range. It would help to do another study with 5-10 of each h/s out of seperate sources so all the cases with the same h/s were made at different years or batches.The way it is now one brand could have had a good batch or bad batch ,but the next batch is completely different. Either way as it is as long as I keep getting free pick-up brass I'll never load a case enough to wear it out.

[FrankenMauser]

AMERC troll? Only 3 postings and touting their brass when thousands of other posts lean in the entire other direction...

I smell fish...

He didn't say it was good brass. His experiment just resulted in more reloadings for the A-Merc case(s). It may be crap, but it's perfectly believable that the alloy might be capable of standing up to more abuse than some other brands.

....Especially since most of the reloaders here don't ever give it a chance.
(I hate it too. I'm not an A-Merc fanboi. But, even crap brass can have a few cases that will take considerable abuse, on occasion.)



Would you believe me if I told you I get fewer reloads out of Norma rifle brass, than any other premium brand, and most common brands?
(Only FC fails before Norma.) Just because it's a premium brand, does not mean the cases will have good longevity. I get better case life out of PMC cases, than Norma... and I HATE HATE HATE PMC rifle brass. (I consider it the A-Merc of the bottle-neck world.)

Overall quality has no real influence on longevity. ...And this was a small sample size.

[orionengnr]

Interesting. I wonder what conclusions (if any) one could draw about a lower-pressure case such as .38 Spl, .45 acp or .45LC.

I would initially think that the .45 acp case, also a short case but with a much lower operating pressure, would be subject to less heat/pressure...but then the work-hardening at the case mouth seems to be the ultimate cause of damage.

The lesson appears to be: bell the case only as much as is necessary, and crimp likewise.

I also wonder how this translates to the life expectancy of a longer, high-pressure case such as .357 Mag or 10mm.

Anyone else care to speculate?

[Snobal]

Sorry I can't help you with data on full-charge loads in .357 Mag brass.

I can say that with Remington brass, I got over 70 loadings from a box of 50, 41 Mag. cases (there were about 35 cases left when I trashed them) and these cases were mostly loaded to about 1,250 fps with cast bullets for deer hunting, practice, etc.

I am currently doing a "torture test" on 50 Starline .357 Mag cases --- mostly loaded to about 800 fps for Bullseye Target Matches and am on re-loading number 64 with 40 of the original 50 cases still "participating" in the test. The others have been retired due to split nicks.

JMHO - YRMV

[orionengnr]

Great input, as I shoot .41 Mag as well. 1250 fps from a .41 Mag is a reasonably stout load, and getting that number of reloads from those cases is astounding. I would have been happy to hear 20-25 load cycles.

Sounds as if having ~1000 rounds of each caliber of revolver brass might just last me the rest of my lifetime, especially as a revolver doesn't try to toss them into the next county (with a 20% loss rate) like my 10mm does.

I have far more .45 acp, and that is the round I shoot most. But even at 10 reloads each, that would keep me busy for an awful long time...

[Sevens]

I've often thought that 1,000 pieces of revolver brass was a nice round number... but it really depends on how many different loads you tend to use and the volume of shooting you do. Simply put, revolver brass lasts a LONG time, and not just because you don't lose it in the weeds. It may go through a bit more flare/crimp, but it doesn't get violently fed & ejected and that means a lot for it's life span.

I can say that with Remington brass, I got over 70 loadings from a box of 50, 41 Mag. cases

This is great data, and I appreciate you sharing it. But I wonder the vintage of your brass, because it's absolutely been my experience that R-P handgun brass is t-h-i-n-n-e-r in the case mouth than almost every other brass I've dealt with. Now that in & of itself doesn't necessarily make it bad brass, but it is maybe the thinnest of everything out there in the case mouth.

I use a good bit of it in .38 Special and I'm splitting case mouths at a noticeable rate. I have other troubles with it, too.

[drmarkwg]

Thanks all! I appreciate the input and suggestions. They will help guide the future research that is already taking shape. I learn a lot from the positive input I get from fellow reloaders.

[BDS-THR]

I have done similar tests using once-fired mixed head stamp cases. What I can add is that tighter chambers that minimize case wall expansion seem to extend case life and makes resizing a breeze.

Using tight chambered Lone Wolf barrels for 9mm and 40S&W and high range W231/HP-38 loads, I stopped the test after 100 reloadings with no case failure.

I do want to add that these testings did not use max loads.

[1SOW]

On another thread that cited this blog, I mentioned I wouldn't use AMerc &:

Interesting blog with interesting findings. One things that matter to me wasn't brought up. (I load 9mm)
1. My "1ST" indication of approaching brass problems is usually the "primer hole" starting to get loose/oversize. I paint the bottom of this case black, shoot it and don't reuse it. The other findings (type of failures) agree with my experience.
2. I also find the F.C. (ATK brass: Speer, CCI, Blazer, *-*) brass to be a little softer than WIN, PPU, R&P. As a consequence they 'feel' and seat bullets slightly differently in a single stage or turret press. They also expand to fill the pistol's chambers differently (better). No big issue here but noticeable.

[Rifleman1776]

I see no point in the study. For practical purposes just use brass until it fails. When I seen an increase in failures I anneal the balance of the batch. I have loaded .44 mag. and 30-06 brass so many times I consider them almost unlimited in their potential life.
If it is OK, use it. If it fails, toss. Nothing to be gained by counting.
BTW, why knock the OP. He believes he is on to something (I don't agree) and may just be a new member.

[drmarkwg]

-- you'd have to be off your rocker to put that much time and energy in to any project where the result is specifically geared to trump up A-Merc component brass.

In my follow up to this study I have determined that the A-Merc brass I used was with all likelihood manufactured by the Olin Corp. So it is for all intents and purposes "Winchester" brass. Made by Olin from the same alloy on the same presses with the same dies except the headstamp die.

[drmarkwg]

Using tight chambered Lone Wolf barrels for 9mm and 40S&W and high range W231/HP-38 loads, I stopped the test after 100 reloadings with no case failure.

Thanks for the valuable input. The tighter the chamber of the weapon being used the less expansion and subsequent contraction during resizing, the less "work hardening" the longer the life of the cases fired through that weapon. Makes sense. Which brass were you reloading?

[drmarkwg]

Interesting blog with interesting findings. One things that matter to me wasn't brought up. (I load 9mm)
1. My "1ST" indication of approaching brass problems is usually the "primer hole" starting to get loose/oversize. I paint the bottom of this case black, shoot it and don't reuse it. The other findings (type of failures) agree with my experience.
2. I also find the F.C. (ATK brass: Speer, CCI, Blazer, *-*) brass to be a little softer than WIN, PPU, R&P. As a consequence they 'feel' and seat bullets slightly differently in a single stage or turret press. They also expand to fill the pistol's chambers differently (better). No big issue here but noticeable.

In the study discussion I mention the LY headstamped brass, because it had primer pockets that were "rattling around" loose. I continued to fire these cases and they eventually failed by splitting at the case mouth. Performance through the weapon was flawless to my surprise. With so many different headstamps I noticed a great deal of variability in the force needed to seat the primers. The standard deviation of the ballistic data tells me that it didn't affect the ballistic performance of the rounds too much. I would like to look at primer pocket fit at some point as well. It will certainly have some effect on the ammo. Thanks

[BDS-THR]

Originally Posted by drmarkwg

Which brass were you reloading?

Mixed head stamp but they were all once-fired.

[Sevens]

If A-Merc is made by the Olin corp, I would like to see a citation of that.

If it is, that will only make me question things coming from the Olin corp, it will not make me think any better of A-Merc brass. There have been countless, countless examples of long time and established handloaders that have shown very clear examples of the problems (usually dimensionally) associated with this brass. I have seen wild dimensional fluctuations in brass from a single box of the stuff.

As for L-Y headstamped brass, that's from Norinco ammunition. My experience with this brass (mine was from the early 90s) is that it may be thicker than others and it may have a smaller capacity. I came to this conclusion because I was seeing high pressure signs specifically in this brass that I wouldn't see in other brass loaded with exactly the same components and the same load, all with components from the same production lot. I was happy with the quality of the brass, but I've discontinued using it to avoid high pressure signs in loads that I know are good loads.

[drmarkwg]

If A-Merc is made by the Olin corp, I would like to see a citation of that.

Getting proprietary information out of the manufacturers is difficult at best. My source on this one is from Lew Curtis. He feels the A-Merc 9MM I used in the study was an early case made by Olin. Subsequent production is likely from RAUG. This is the kind of information I am finding I have to rely on, as the Olin Corp. has yet to respond to requests for information. Trade secrets and proprietary information make it difficult to say with any certainty where a particular case was manufactured, which alloy they used and which process was used. Headstamp alone is not a good indicator of who made the brass. Lew is a very reliable source of information on 9mm though.

This is precisely the information I would like to have to interpret the data I gathered. If you have any citations or reliable and verifiable information on any of the brass used in the study I am in the process of following up with that information. Please share. Thanks