45acp Case Longevity Article

C

CQB45ACP

Member
Joined
Nov 10, 2020
Messages
5,455
Location
Northern Virginia at the Beltway
I’ve linked to a great article on testing case longevity for 45acp. For all I know it was written by one of you.

Some key takeaways—

Using new Starline cases measuring .894”, after 20 firings they measured SAAMI minimum .888”.

Cases shortened after each firing and at the head, not mouth.

While cases got shorter with each firing, after 54 they were never short enough to headspace off the extractor.

Case mouth did not get thicker after firings.

After 30 firings, primer pocket had become shallower to the point primer wouldn’t fully seat and kept getting shallower.

Test ended after 54 firings not because of splitting or other failure but because primer could not be safely seated.

Hope you find this as interesting as did I.

How many times can I reload 45 ACP brass? – Florida Reloading

www.floridareloading.com www.floridareloading.com
 
CQB45ACP said:
I’ve linked to a great article on testing case longevity for 45acp. For all I know it was written by one of you.

Some key takeaways—

Using new Starline cases measuring .894”, after 20 firings they measured SAAMI minimum .888”.

Cases shortened after each firing and at the head, not mouth.

While cases got shorter with each firing, after 54 they were never short enough to headspace off the extractor.

Case mouth did not get thicker after firings.

After 30 firings, primer pocket had become shallower to the point primer wouldn’t fully seat and kept getting shallower.

Test ended after 54 firings not because of splitting or other failure but because primer could not be safely seated.

Hope you find this as interesting as did I.

How many times can I reload 45 ACP brass? – Florida Reloading

www.floridareloading.com www.floridareloading.com
Click to expand...
Thanks for posting. Quite interesting.
 
Very interesting.
While I didn't necessarily expect the case mouth to split (taper crimps have to be much easier on the case mouth than roll crimps) I didn't expect the case length to shrink at the extractor groove.

Makes sense now but didn't before I read the article.

I chose this particular piece of brass to keep an informal eye on.

Absent-mindedly, I never thought to take measurements or even record the amount of firings but ,some quick math puts it (conservatively) around 20-25 loadings.

I would've thought the headstamp would've been getting faint by now though.

20230813_095431.jpg
 
Y-T71 said:
Very interesting.
While I didn't necessarily expect the case mouth to split (taper crimps have to be much easier on the case mouth than roll crimps) I didn't expect the case length to shrink at the extractor groove.

Makes sense now but didn't before I read the article.

I chose this particular piece of brass to keep an informal eye on.

Absent-mindedly, I never thought to take measurements or even record the amount of firings but ,some quick math puts it (conservatively) around 20-25 loadings.

I would've thought the headstamp would've been getting faint by now though.

View attachment 1166553
Click to expand...
You’re right. That headstamp’s in surprisingly good shape.

I’m in the midst of a Winchester only rotation of about 200 cases. The purpose of which was originally to see how long they last.

Now I’m changing the target and am replacing as they shorten to an as yet undetermined length with the longest length I have available at the time.
 
CQB45ACP said:
You’re right. That headstamp’s in surprisingly good shape.

I’m in the midst of a Winchester only rotation of about 200 cases. The purpose of which was originally to see how long they last.

Now I’m changing the target and am replacing as they shorten to an as yet undetermined length with the longest length I have available at the time.
Click to expand...

I might try to join you in your quest for data; I'm pretty lazy though so, I'll look forward to seeing your results.

Someday, when all .45acp brass is SPP, I'll certainly regret my decision!
 
CQB45ACP said:
Using new Starline cases measuring .894”, after 20 firings they measured SAAMI minimum .888”.

Cases shortened after each firing and at the head, not mouth.
Click to expand...
Disclaimer: I don't live in FL and not a NRA certified instructor.

Thanks for the article and reading through, can appreciate the methodology and approach to objective testing I employ for my "myth busting/confirming" threads.

Article finding does confirm what we have posted on THR that brass case gets shorter from repeated firing due to case base expansion not resized by the carbide sizer ring.

Another article on "Case Longevity" tested .38 Spl and confirmed work hardening that led to case split and nickel plated cases having less case life than brass cases both of which we posted on THR as well - http://www.floridareloading.com/index.php/2017/02/04/cartridge-case-longevity/

But as both articles mentioned, .45ACP and .38 Spl are low pressure cartridges operating to 21,000/17,500 PSI compared to 35,000 PSI for 9mm. When I did my "real world" case longevity test with 9mm mixed range brass, cases did get shorter with subsequent reloadings but I had to stop the test around 20-30 reloadings depending on headstamp as primer pocket started to loosen and cases split.

For better testing approach, since I have brand new RMR 9mm brass, I could repeat the myth busting transitioning from smaller diameter primers to larger Metric primers if primer pockets enlarge. I have welded landscaping trailer my BIL built for me as retirement present that I was thinking about using as mobile shooting platform (pistols/rifles bolted to frame) with tri-pod base to ground under the frame but I could readily do a reloading set up for case longevity test for 9mm.
 
Interesting article. Thanks for posting. I've always been in the camp who shoots them until they split, and can't say I've noticed high primers. Some of my brass goes back to the 50s and 60s, so there's no telling how many times they've been loaded. Out of curiosity, I just pulled ten old .45 Auto cases and measured their lengths. Sure enough, most are below the SAAMI 0.888" min length. (I'll assume they started out longer.)

WWC 63 = 0.880"
WWC 89 = 0.882"
WWC 63= 0.883"
WWC 72 = 0.883"
WWC 84 = = 0.883"
WWC 68 MATCH = 0.880"
WRA 56 = 0.882"
TZZ 85 = 0.889"
RA 63 = 0.886"
RA 68 = 0.886"

I wonder if there is a point at which the shrinking stops? This also begs another question, how short is too short, since shooting .45s until they split is a pretty common practice? I can understand it may likely affect precision for bullseye shooting, but functionally, I've not experienced or heard of any issues.
 
Last edited:
LiveLife said:
Disclaimer: I don't live in FL and not a NRA certified instructor.

Thanks for the article and reading through, can appreciate the methodology and approach to objective testing I employ for my "myth busting/confirming" threads.

Article finding does confirm what we have posted on THR that brass case gets shorter from repeated firing due to case base expansion not resized by the carbide sizer ring.

Another article on "Case Longevity" tested .38 Spl and confirmed work hardening that led to case split and nickel plated cases having less case life than brass cases both of which we posted on THR as well - http://www.floridareloading.com/index.php/2017/02/04/cartridge-case-longevity/

But as both articles mentioned, .45ACP and .38 Spl are low pressure cartridges operating to 21,000/17,500 PSI compared to 35,000 PSI for 9mm. When I did my "real world" case longevity test with 9mm mixed range brass, cases did get shorter with subsequent reloadings but I had to stop the test around 20-30 reloadings depending on headstamp as primer pocket started to loosen and cases split.

For better testing approach, since I have brand new RMR 9mm brass, I could repeat the myth busting transitioning from smaller diameter primers to larger Metric primers if primer pockets enlarge. I have welded landscaping trailer my BIL built for me as retirement present that I was thinking about using as mobile shooting platform (pistols/rifles bolted to frame) with tri-pod base to ground under the frame but I could readily do a reloading set up for case longevity test for 9mm.
Click to expand...
Yes it certainly confirmed the shortening issue. And by identifying 20 firings to hit the SAAMI minimum, one could calculate the “cost” (in terms of shorter lifespan) of even the slightest trimming of an 45acp case.

But that presumes one places SAAMI length as the lifespan limit which is arbitrary.
 
LiveLife said:
Article finding does confirm what we have posted on THR that brass case gets shorter from repeated firing due to case base expansion not resized by the carbide sizer ring.
Click to expand...

Would a Redding dual ring sizing die help with this issue? I'm a little hazy about the benefits of that die.
 
Gone Hiking said:
Interesting article. Thanks for posting. I've always been in the camp who shoots them until they split, and can't say I've noticed high primers. Some of my brass goes back to the 50s and 60s, so there's no telling how many times they've been loaded. Out of curiosity, I just pulled ten old .45 Auto cases and measured their lengths. Sure enough, most are below the SAAMI 0.888" min length. (I'll assume they started out longer.)

WWC 63 = 0.880"
WWC 89 = 0.882"
WWC 63= 0.883"
WWC 72 = 0.883"
WWC 84 = = 0.883"
WWC 68 MATCH = 0.880"
WRA 56 = 0.882"
TZZ 85 = 0.889"
RA 63 = 0.886"
RA 68 = 0.886"

I wonder if there is a point at which the shrinking stops? This also begs another question, how short is too short, since shooting .45s until they split is a pretty common practice? I can understand it may likely affect precision for bullseye shooting, but functionally, I've not experienced or heard of any issues.
Click to expand...
Don’t know about when shrinking stops but as for how short is too short, it’s touched on in a thread I started last week about trimming 45acp cases and @LiveLife provided reasons why not to trim. Takes some scrolling through but if you’re really interested…https://www.thehighroad.org/index.php?threads/trimming-auto-pistol-cases-is-unnecessary-waste-of-time-so-that’s-what-i’m-doing.921544/
 
In theory, a Lee “Bulge Buster” kit would resize the base and rim to SAAMI max (or thereabouts) but I’m not sure if or how that would stretch the case back to nominal. Maybe use a smaller (.40S&W) punch and run cases through base first?
Ask Mister Owl?
 
I read that article about five years ago when I first started reloading. I was wondering how many times I could safely reload my 45 acp. As I recall he was loading the round with a max charge because he was trying to see how long before the case would split, and the results he saw were quite different from his expectations and quite informative as well.

chris
 
I wonder how much longer the cases will last by not sizing to factory specs and reloading with .452 sized bullets like manufacturers recommend to get over 100 uses from each casing.
Nothing wrong with undersizing, it's choice, just dont expect 100 uses.
I compared resizing brass to spring compression, it literally is the same thing. Everytime the case is fired its like decompressing a spring. Everytime the case is sized its like compressing the spring. Hotter rounds are like decompressing a spring to its max or more, and sizing to factory is like compressing a spring to the max, or more(like overloading a magazine)
Downloading mags by 1 or 2 rounds can extend spring life and increase(or maintain) strength. Over stretching mag springs can prematurely wear them even if they give a temporary increase in feeding strength.
Just my 2 cents. FWIW
 
I've been reloading since about 1980 and 45 ACP has been one of the main cartridges. I lose more cases to the "Bermuda Triangle" than to any other failure/loss mode. So, I won't disagree with the article posted by the OP.

While I hate to lose good cases, I figure some loss goes with the territory. Over the past 10-15 years, I;ve been able to shoot off my back porch, and my losses have greatly been reduced.
 
Gunfu_Blaster.45 said:
I wonder how much longer the cases will last by not sizing to factory specs and reloading with .452 sized bullets like manufacturers recommend to get over 100 uses from each casing.
Nothing wrong with undersizing, it's choice, just dont expect 100 uses.
I compared resizing brass to spring compression, it literally is the same thing. Everytime the case is fired its like decompressing a spring. Everytime the case is sized its like compressing the spring. Hotter rounds are like decompressing a spring to its max or more, and sizing to factory is like compressing a spring to the max, or more(like overloading a magazine)
Downloading mags by 1 or 2 rounds can extend spring life and increase(or maintain) strength. Over stretching mag springs can prematurely wear them even if they give a temporary increase in feeding strength.
Just my 2 cents. FWIW
Click to expand...
I think you’re right…and undersizing PLUS using .452 bullets would seem to be even more stress. That’s what I do but just recently started testing my Winchester batch so have lots of life left in my cases being tested—or do I
 
Along with trimming and chamfering, I think you need to anneal them, roll size, and hydro form…
Interesting articles and I await your findings!
 
CQB45ACP said:
Test ended after 54 firings not because of splitting or other failure but because primer could not be safely seated.
Click to expand...

ONLY 54 firings using a max load on a semi-auto pistol round??? ....and never have to trim??? lol
I would likely lose any ejected semi-auto pistol brass before I could reload it that many times. But, if I managed to reloaded such a case 50+ times, I'd probably frame it, and proudly display it above my bench. lol

PS, they should have gotten some tighter fitting metric primers and kept on going! :)
 
n2omike said:
PS, they should have gotten some tighter fitting metric primers and kept on going! :)
Click to expand...

If I remember the article correctly, the pockets didn't get loose, rather they got shallow so that the primer when seated completely was actually sitting above flush.

I have some 45acp where the headstamp is almost unreadable, so no telling how many times they've been reloaded.

chris
 
My experience with 308 brass showed me the primer pocket collapses over time. I believe this is due to the spreading outward of the case head, and an internal collapse of the primer hole area. This can all be fixed by reaming the pocket to depth.
 
You must log in or register to reply here.

Similar threads

C
45acp Case Longevity Test Update
Replies
14
Views
420
CQB45ACP
C
C
45ACP Case Longevity Update (Updated Again)
Replies
17
Views
420
CQB45ACP
C
C
45acp Case Life Longevity Test Update (non-scientific)
2
Replies
31
Views
1K
Soonerpesek
Soonerpesek
C
45acp Case Longevity Test Update
Replies
1
Views
112
Shovel
Shovel
C
45ACP Case Longevity Test Update
2 3 4 5
Replies
101
Views
2K
CQB45ACP
C
Back
Top