9mm Winchester Case Longevity Test Update--33rd Shooting

[CQB45ACP]

I don't update on this test as often as the 45acp test because there's less happening. I like it that way.

Started test June 2023. As title says just finished 33rd shooting. Photo shows priming 120 cases. There are another 60 already loaded in mags. Started test with 200. Again, all Winchester.

Have had six case failures--five vertical splits, one crack partially around the base circumference. One split found this go round. I caught it visually before resizing after Monday's shooting. I typically catch them by feel while sizing or seating. Can't recall another visual catch. Photo shows seven but one is an FC and thus not part of test.

FYI, I don't measure case length nor play around with primer pockets except I did uniform them nearly a year ago. So, I don't know if these are growing, shrinking, tightening, etc, as are the 45acp cases.

Why am I doing this? Out of curiosity & in solidarity with my 45acp test. No other reasons.

Anyway, enjoy (or not)

This has been updated, below--eight case failures!

 

[tightgroup tiger]

Have you noticed them getting harder to resize?

 

[CQB45ACP]

Have you noticed them getting harder to resize?

No I haven’t but it’s only every several weeks so might not realize it.

Besides, 9mm are little girls.

 

[LiveLife]

9mm ... just finished 33rd shooting ... Have had six case failures--five vertical splits, one crack partially around the base circumference. One split found this go round ... FYI, I don't measure case length nor play around with primer pockets

Why am I doing this? Out of curiosity & in solidarity with my 45acp test. No other reasons. Anyway, enjoy (or not)

Nice. I am the curious type, like you.

And I like longevity (15,000+ 22LR accuracy comparison), testing to point of failure (Lee press/product beta/product testing), "real world" testing (50 yard groups with "cheap" 22LR), myth busting/confirming threads (Digital scale accuracy, zero drift, etc.).

When I did my 9mm case longevity testing with KKM 40-9mm conversion barrel; around 30th reloadings, I started to get split cases and loose primer pockets. I was shooting for 50+ reloadings but I started with mixed range brass with unknown reload history so my test methods/results were "flawed/contaminated" right from the start.

I bought new RMR headstamp brass to use as 9mm reference testing and thought about doing longevity testing of cases but I am busy with other projects (Finishing 22LR 50 yard testing, starting .223 55/62/69/75 gr 100 yard testing, testing new RMR 40S&W 180 gr TCFP in Glock 22/JR Carbine) and my fishing buddies found me a nice 300-400 yard shooting spot and I am cutting up 3/8" steel plates to use as targets as we speak.

Keep up the good work.

 

[CQB45ACP]

Nice. I am the curious type, like you.

And I like longevity (15,000+ 22LR accuracy comparison), testing to point of failure (Lee press/product beta/product testing), "real world" testing (50 yard groups with "cheap" 22LR), myth busting/confirming threads (Digital scale accuracy, zero drift, etc.).

When I did my 9mm case longevity testing with KKM 40-9mm conversion barrel; around 30th reloadings, I started to get split cases and loose primer pockets. I was shooting for 50+ reloadings but I started with mixed range brass with unknown reload history so my test methods/results were "flawed/contaminated" right from the start.

I bought new RMR headstamp brass to use as 9mm reference testing and thought about doing longevity testing of cases but I am busy with other projects (Finishing 22LR 50 yard testing, starting .223 55/62/69/75 gr 100 yard testing, testing new RMR 40S&W 180 gr TCFP in Glock 22/JR Carbine) and my fishing buddies found me a nice 300-400 yard shooting spot and I am cutting up 3/8" steel plates to use as targets as we speak.

Keep up the good work.

Thanks. On the loose primer pockets, were there any early signs beyond the "feeling" that it seated too easily? I know, it's a lame question, what else would a symptom be? I actually hadn't given it much thought, but I was using Servios and they feel differently anyway. Maybe I'll go back to CCI.

 

[LiveLife]

On the loose primer pockets, were there any early signs beyond the "feeling" that it seated too easily?

Yes, seated primers falling out of pocket.

I marked these with "X" on the base and left them on the range floor.

 

[1KPerDay]

Interesting. Personally I'd scrap the whole batch once I started seeing case splits and loose primer pockets. However I appreciate your data gathering and sharing.

 

[LiveLife]

33rd shooting ... all Winchester

Interesting. Personally I'd scrap the whole batch once I started seeing case splits and loose primer pockets. However I appreciate your data gathering and sharing.

Even all same headstamp, if they are mixed range brass, rate of case wall failure/splits from work hardening of brass will vary. (Hence the testing. )

Both of our testing revealed 9mm mixed range brass should be good for around 30+ reloadings before case neck starts splitting to use as "reference info".

 

[GeoDudeFlorida]

I’m still waiting for the results of the Tootsie Pop test

 

[Soonerpesek]

I’m still waiting for the results of the Tootsie Pop test

Thrrrrree…….three licks to the center…

 

[SterlingBullet]

Thin brass survives 33 explosions.
The miracle of modern meturallgy.

Much like the durability of engine pistons and chambers at high RPMs for thousands of hours/miles.

I'm glad I was born in the 20th century. The things we get to use and experience.

 

[CQB45ACP]

Thrrrrree…….three licks to the center…

I never could pass it...a minute or so and crunch, it's over.

 

[CQB45ACP]

A re-update and it's exciting...two more failed (cracked) cases found during expanding. That makes a total of eight split 9mm cases after 33.5 loadings. (Not really sure how to count since I'm mid way between 33rd and 34th)

 

[CQB45ACP]

Interesting. Personally I'd scrap the whole batch once I started seeing case splits and loose primer pockets. However I appreciate your data gathering and sharing.

I understand the sentiment, but if I did that you couldn't tell your grandkids about the guy on THR who had a monkey on his back.

 

[GeoDudeFlorida]

A re-update and it's exciting...two more failed (cracked) cases found during expanding. That makes a total of eight split 9mm cases after 33.5 loadings. (Not really sure how to count since I'm mid way between 33rd and 34th)

View attachment 1230694

They only survived 33 loadings, cracked when being loaded the 34th time, but at an early stage of the process, so how about 33-1/3?

 

[lordpaxman]

Thanks for the update. But I’m a little concerned about the ISO9000 record keeping…

I’m pretty sure I lose my cases before they approach 30!

 

[CQB45ACP]

Thanks for the update. But I’m a little concerned about the ISO9000 record keeping…

I’m pretty sure I lose my cases before they approach 30!

One of the obscure pleasures of retirement...I don't need to know about ISO9000!

 

[Soonerpesek]

I’m pretty sure I lose my cases before they approach 30!

Since I turned 30 (years agoooo), I lose alot of stuff…!!

 

[GeneS]

CQB45, thank you for reporting your results. This kind of info is really interesting to an old brass scrounger like me. Sorry if I overlooked it but, I'm guessing you are loading these fairly light (or middle of the road), as you did with the .45 auto test?

 

[CQB45ACP]

CQB45, thank you for reporting your results. This kind of info is really interesting to an old brass scrounger like me. Sorry if I overlooked it but, I'm guessing you are loading these fairly light (or middle of the road), as you did with the .45 auto test?

Thank you and yes, light/middle--115gr plated/fmj RN & 4.5gr Sport Pistol.

My hands are old and take precedence over testing

 

[bigpower491]

Thanks for the update. But I’m a little concerned about the ISO9000 record keeping…

I’m pretty sure I lose my cases before they approach 30!

Good lord man he'd need to take up 3 pages of posts doing ISO9000, just to tell us 8 cases split at 33-1/3 loads

 

[GeneS]

Thank you and yes, light/middle--115gr plated/fmj RN & 4.5gr Sport Pistol.

My hands are old and take precedence over testing

Thanks again, and good luck however far you go with this. Just the thought of trying to find the same 200 9mm cases for over 30 times is too much for me.

 

[CQB45ACP]

Thanks again, and good luck however far you go with this. Just the thought of trying to find the same 200 9mm cases for over 30 times is too much for me.

I underestimated how annoying THAT would be. Really detracts from fun at range.

 

[bigpower491]

Thanks again, and good luck however far you go with this. Just the thought of trying to find the same 200 9mm cases for over 30 times is too much for me.

I underestimated how annoying THAT would be. Really detracts from fun at range.

Yea that crossed my mind as well. I try to keep the grass on the range super short, but still can only come up with 75-80% recovery shooting auto loaders. I'd like to find a good used reel mower for the tractor and cut it like a putting green, but the decent ones I've come across are not cheap. Hats off to the patients for that

 

[CQB45ACP]

Yea that crossed my mind as well. I try to keep the grass on the range super short, but still can only come up with 75-80% recovery shooting auto loaders. I'd like to find a good used reel mower for the tractor and cut it like a putting green, but the decent ones I've come across are not cheap. Hats off to the patients for that

Well I ahoot indoors so cutting grass shorter isn’t an option. But believe me don’t let the green monster putting green idea take hold.

Here’s my colonial bentgrass green cut at 1/4”+ using a Toro Greensmaster. Have to cut it about every other day but it likes every day better.

Looks great? Yeah until I lost nearly all of it this year to excessive heat and drought beyond my ability to keep up. Waaay too much work for most homeowners.