38 Special brass, how many reloads before it morphs into 357

[drone]

As the header says, how much do 38 special cases stretch when reloading at subsonic velocity and FL resizing?
Do they ever get so long that they fill a carbine 357 mag chamber?

[GasGuzzler]

I don't think a case can grow an 1/8" without blowing out first.

[farmerjim]

I have never known straight wall cases to grow enough to need trimming

[RBHarter]

I don't know about 38s but my 45 Colts at 35-40 cycles have gone from 1.285 down to 1.260 .

I've run loads from the bluper that bounced off a 25 yd backer to a 1200 fps 350 in a carbine and well into the Ruger only levels . Those 300 aren't used up yet but are very likely to become 45 S&W .

[Fyodor]

I use some of mine for close to ten years now. .38spl cases are built like tanks. Occasionally I have a split one, of one is stepped upon, but I never had one that was significantly lengthened. I even stopped measuring it years ago.

[Reefrman]

Only time I ever trim pistol brass are new ones for my 357 and 44 magnum nuclear loads so crimps are the same.

[drone]

That's really good news, I have some winchester cases and also PPU, hopefully they won't stretch..

[RBHarter]

As a rule straight wall cases don't grow they get shorter . The ACP clans will eventually show the collapse of the extractor groove.

[Royce]

I had to trim some 45 Colt cases because they were too long according to SAAMI specs. That was the only time I have had to trim pistol brass. I've reloaded 38 Special cases for decades. None of them have ever given me any trouble.

[Maven]

My experience is just the opposite. I.e., my .357mag. brass grows shorter after several light - moderate loadings. Those then become .38Spl. brass after trimming to length of course.