Yoicks! Straight-wall cases DO stretch!

[Col. Harrumph]

Reloading some .357 mags for the Ruger, which has been feeling kinda left out lately. So: 16.9 gr H110, Federal SPM's, Hornady 158 gr HTPs, brass is headstamped CBC which Google says is made in Brazil (and seems OK, Magtech sources from them). Anyway, I scrunched this one today, as shown:

This wasn't too bad; it still chambers. But what gives? The die hasn't moved and is still in adjustment. The only thing I can think of: The case stretched to the point it hit the crimp step before the bullet was fully seated. I've never bothered to check case length with straight wall handgun brass; I guess I'll have to change that. (Sorry for the soft focus.)

BTW, just because I load 16.9 grains of H110 doesn't mean you should. Take it easy!

 

[mcb]

Some straight wall case shrink. Push 450 Bushmaster right up to the pressure limits and the case head expansion with make them shorter and even after sizing you won't get all that length back.

 

[Atavar]

I have this argument all the time. I have to trim cases frequently for pistol cases I am going to roll crimp. If they don’t stretch they must have been hella long from the factory.
When I trim I measure the cases I am going to use and trim to the middle of spec and toss the short ones.

 

[mcb]

I have reloaded tens of thousand of 40S&W, 45 ACP, 38 Short Colt and 38 Special and never trimmed a pistol case but I am not a big fan of crimping in general so that might explain it.

 

[AJC1]

I have this argument all the time. I have to trim cases frequently for pistol cases I am going to roll crimp. If they don’t stretch they must have been hella long from the factory.
When I trim I measure the cases I am going to use and trim to the middle of spec and toss the short ones.

I trim them initially, but careful attention shows that second trimmings are just squaring back up...

 

[DILLONHELP]

Measure the overall length on 5 or 6 fired cases. Size them, then remeasure. It is also possible that the cannelure is not in a uniform place on each projectile either.

 

[AJC1]

Measure the overall length on 5 or 6 fired cases. Size them, then remeasure. It is also possible that the cannelure is not in a uniform place on each projectile either.

I had that happen on a 150 grain Sierra 30-30 bullet. It just looked wrong so I pulled it just to check. Still sitting in a bag ready to go bang...

 

[mdi]

I have been reloading straight walled cases for my revolvers since the beginning. After many handloads of 7 different calibers, I still separate seating and crimping. I also check every die adjustment every time I use them (I even check die adjustment when using my Co-Ax). Even if I am reloading the identical handload again I double check every step. I can't remember the last time I measured the case length for any handgun brass I use...

 

[JKP]

When I used to shoot 44 mag a lot, I did trim some cases that were too long. They wore out before needing a second trim.

 

[GeoDudeFlorida]

Every blue moon or so I’ll feel resistance on the handle before the die bottoms out while seating/crimping. I just stop there and check to see if the crimp looks good. I can’t remember the last time I wrinkled a case so I guess going slow and paying attention to handle resistance might mitigate the need for trimming. (?)

RCBS Partner (SS) press. Sometimes I seat and crimp in one step and sometimes I seat then crimp. It just depends.

 

[Walkalong]

My light plinking load .357 cases need trimming one time, then they are good to go. Eventually, some of my full power .357 cases need another trim, the softer cases I assume.

 

[drband]

I think full power with a heavy crimp is the usual cause for needing another trim. I don’t load like that , so trim once at the beginning— done!

 

[cfullgraf]

For the most part, for handgun cases that get a roll crimp, its trim once and done.

When I as shooting 357 Mag in IHMSA handgun silhouette, the cases might need additional trimming after a few firings to maintain a consistent crimp between caes.

Now, 30 Carbine is another matter. Yes, it is not strictly a "handgun" round nor formally fired in a handgun for the most part. I need to trim 30 Carbine after every few firings.

Handgun cartridges that get a taper crimp never get trimmed.

 

[crestoncowboy]

My 460 cases are the only ones I've had enough stretch to worry with.

 

[theotherwaldo]

I check my cases for length every time that I reload because I often wind up getting range brass mixed in with my brass.

I make length gauges for each caliber, made from two 4" repair brackets held together and spaced apart by two stove bolts, four lock washers and six nuts. The repair brackets are spaced at minimum case length at one end, max at the other.

Each gauge is marked with caliber using a whiteout pen.

I don't use maximum loads in any of my firearms - if I want something more powerful then I buy something designed to fire something more powerful. Anyway, I find that maximum accuracy is normally found in the moderate loads... .

 

[.45Coltguy]

The only straight wall cases I've trimmed were "American Eagle" .357 cases after first fire. Those cases were long; 1.298" or more. One trim, that was the end of trimming those.
Only ones that ever needed trimming.

 

[Atavar]

It’s not the absolute length of the cases that causes a problem, but the difference between the shortest and longest case in a batch. If that difference is more than a few thousandths it can cause problems with roll crimp.

 

[.45Coltguy]

It’s not the absolute length of the cases that causes a problem, but the difference between the shortest and longest case in a batch. If that difference is more than a few thousandths it can cause problems with roll crimp.

That's why I seat and crimp in two seperate steps. It just makes my life easier.