9mm Case Longevity Test--39th Firing

[lordpaxman]

No, I'm not--annealing nor polishing.

If you would be so kind to refresh my memory as to your preferred tumbling method, if at all?

And thanks for the dedication to tracking these cases - I only shoot range brass so it’s nice to know all that unknown brass history may not make a big difference. At least for pistol rounds.

 

[CQB45ACP]

38 special brass does eventually fail but it’s an inter-generational testing program. I’m getting a lot of splits in Rem-UMC brass lately. That brass is probably from the 1930s and has been passed down since my great grandfather loaded it. He didn’t keep any notes on pistol loads, but the powder dipper made from a trimmed 45 auto case with a nail soldered into it probably gives the right amount of DuPont 80 powder. I still use them but 1-2 split per 100 now. I could anneal but I needed together to the minimum for free shipping on something else so now there are 100 new starline cases for my great grandchildren to puzzle over.

I‘m just impressed you can keep track of brass through 39 loadings.

You know it's stories like yours that caused me to do this. I just had to find out for myself.

Indoor range, Monday when they first open, at most three other guys, first lane on the left...kinda like my reserved barstool. Unless brass goes over firing line quite a way, I can retrieve it.

 

[CQB45ACP]

If you would be so kind to refresh my memory as to your preferred tumbling method, if at all?

And thanks for the dedication to tracking these cases - I only shoot range brass so it’s nice to know all that unknown brass history may not make a big difference. At least for pistol rounds.

Thank you

Wet with pins and cascade dishwasher pods. I like it shiny, gleaming...jewelry

Everything I shoot is range brass from three or four years ago. But I'll wager it's once fired. Can't prove it but I'm the only scrounger I ever see.

And just moderate loads if that makes a difference.

 

[CQB45ACP]

@MarshallDodge you asked about headstamp condition. Sorry I'm not a better photographer, but the general condition is visible--look pretty good to me.

 

[Hooda Thunkit]

I‘m just impressed you can keep track of brass through 39 loadings

This. I shoot out behind the barn right here on my property, with a brass-catching net mounted in a tripod right next to the ejection port of the pistol.

And i still lose 2 or 3 pieces every time.

 

[CQB45ACP]

BTW, @blackd24 more info potentially impacting neck tension:

I use a Lee undersized sizing die every time, their "M" style expander every time, and occasionally as needed a 9mm Mak die to bulge bust an empty case or two.

And when needed, an FCD for any crimping needed (maybe 25% of the time).

In other words these cases get a complete workout.

PS--why they need a bulge busting I have no earthly clue.

 

[Pat Riot]

Originally 200 Winchester cases only.

Just curious. Were these Winchester “white box ammo” cases?

 

[CQB45ACP]

Just curious. Were these Winchester “white box ammo” cases?

Maybe, but don't know. It's whatever folks shot at my range. When I first started reloading, I bought bags of 500 used cases until I had enough.

 

[jmorris]

I‘m just impressed you can keep track of brass through 39 loadings.

I hear it's easy when you cut your grass with cuticle scissors...

 

[Pat Riot]

Maybe, but don't know. It's whatever folks shot at my range. When I first started reloading, I bought bags of 500 used cases until I had enough.

Have you ever had to trim them?

 

[jmorris]

Maybe, but don't know. It's whatever folks shot at my range. When I first started reloading, I bought bags of 500 used cases until I had enough.

At 39 firings a case 500 of them will be good for almost 20,000 rounds.

 

[CQB45ACP]

At 39 firings a case 500 of them will be good for almost 20,000 rounds.

sounds like a plan

 

[CQB45ACP]

Have you ever had to trim them?

No thank goodness. And, unlike my 45acp test, I've never even measured these.

 

[GeoDudeFlorida]

No thank goodness. And, unlike my 45acp test, I've never even measured these.

I’ve come to the conclusion that headspacing off the rim is not quite the disaster the scuttlebutt would have us believe

 

[CQB45ACP]

Got curious as to case length. Wish I hadn't. SAAMI is .754"-.744"

Nearly half of the ones I measured are shorter than SAAMI minimum. A few way shorter. Now, are expanded cases shorter than those simply resized?

Also gotta wonder, do 9mm shrink like 45acp did? Looks that way. But, just going to shoot these anyway.

 

[Soonerpesek]

Got curious as to case length. Wish I hadn't

The seed was planted..............

 

[Pat Riot]

Got curious as to case length. Wish I hadn't. SAAMI is .754"-.744"

Nearly half of the ones I measured are shorter than SAAMI minimum. A few way shorter. Now, are expanded cases shorter than those simply resized?

Also gotta wonder, do 9mm shrink like 45acp did? Looks that way. But, just going to shoot these anyway.
View attachment 1253404

Now I’m sorry that I brought it up.

That’s really strange. I would have thought that like rimmed cases, they would stretch over time.

In my experience expanded cases are usually just a couple thousandths shorter than resized cases on .38 Spl and .357 Magnum. On .45 Colt maybe .005”. I have never tested 9mm.

 

[CQB45ACP]

Now I’m sorry that I brought it up.

That’s really strange. I would have thought that like rimmed cases, they would stretch over time.

In my experience expanded cases are usually just a couple thousandths shorter than resized cases on .38 Spl and .357 Magnum. On .45 Colt maybe .005”. I have never tested 9mm.

My 45acp test cases began at .893" and above and after 33 firings were as short as .882". SAAMI is .888"

The reason I never measured the 9mm was to avoid the same time suck as the other test.

 

[Soonerpesek]

The reason I never measured the 9mm was to avoid the same time suck as the other test.

I'd have to say that the majority of us have/are enjoying the testing.......

 

[CQB45ACP]

Now I’m going to be measuring case lengths after every firing. Oh boy.

 

[GeoDudeFlorida]

My 45acp test cases began at .893" and above and after 33 firings were as short as .882". SAAMI is .888"

The reason I never measured the 9mm was to avoid the same time suck as the other test.

You have something better to do?

 

[CQB45ACP]

You have something better to do?

Well, it's not the measuring, per se, it's the follow-up action. Write it all down? Ignore it? Toss cases under x length? Post a thread on THR? The decisions are paralyzing..

 

[GeoDudeFlorida]

Well, it's not the measuring, per se, it's the follow-up action.

Write it all down?

Obviously.

Ignore it?

wuuuht? Never!

Toss cases under x length?

Meh. I’d just run them but that’s me.

Post a thread on THR?

Obviously!

The decisions are paralyzing..

Analysis Paralysis. It’s real.

 

[Berserker]

When shooting, do you know which one failed, with respect to target? I have been curious how brass failure effects POI. Plinking might matter so much.

 

[CQB45ACP]

When shooting, do you know which one failed, with respect to target? I have been curious how brass failure effects POI. Plinking might matter so much.

No, not while shooting. All the failures I’ve had on these or others have been found when resizing, expanding, or seating. I wouldn’t be surprised if they affect performance but I just haven’t experienced it or been astute enough to pick up on it.