Case Trimming Question(s)

[Buckey O'Neill , SASS Life #42761]

Re-loading manuals show a "Max. Case Length", and just below that it lists a "Case Trim Length" which is shorter. Example for .44-40 Winchester:

Max Case Length: 1.305"

Case Trim Length: 1.295"

 

Curious as to why two different case lengths listed.

 

I full-length re-size without expanding the case mouth and then trim my cases to the specified Case Trim Length for new and fired cases.

 

[Perro Del Diablo]

To allow for cartridge stretch. Or look at a tolerance your minimum safe length and maximum safe length. 

[Mogollon Munk,SASS#303]

SAAMI tolerances allow a maximum case length, and the minimum case length is .020" shorter on 44-40. 1.305 +.000, -.020".

Fired cases stretch after resizing, so check case length on fired, resized cases to determine if trimming is necessary.

[Cowtown Scout, SASS #53540 L]

I have trimmed bottle neck rifle cases before but never any pistol cases.

[Reverend P. Babcock Chase]

Howdy Trimmers,

 

One reason not mentioned for trimming cases to the same length is get consistent crimps. I had a devil of a time with my .45 crimps until I checked the lengths of my mixed collection of cases. They were all over the place. Once trimmed to a consistent length, the crimp problems went away.

 

Rev. Chase

[The Original Lumpy Gritz]

Trim AFTER sizing 

[Garrison Joe, SASS #60708]

That difference in lengths is to allow a firing or two (each stretching the length a little) on bottleneck RIFLE cases, otherwise rifle shooters would have to trim every time they fire their cases.   Lots of work.  So, trimming is done a little short of the "critical" too-long dimension.

 

Trimming pistol cases is RARELY needed, the pressures are lower and there is no bottleneck shoulder to help stretch the case lengthwise.   .45 Auto cases even SHORTEN with 20 or so firings.

 

good luck, GJ

[Griff]

Measure your new, unfired pistol brass, trim those that need it & you'll more'n likely never need to trim again.  Although I load them up in the trimmer, very seldom do they actually need a trim.  The only cases (new) I don't bother with are the C45S... since they're going into a 45 Colt chamber, no length worries... and what I've found over the 1K or so cases I've used is that they're fairly consistent from Starline.   

[Rooster Ron Wayne]

I have been reloading longer then I can remember anymore. 

I have Never had to trim any brass used for SASS .

You just don't build enough presher to stretch the brass .

It will usually split long before it stretches out .

So Saith The Rooster 

[Go West]

I don't trim pistol brass, ever. There are more fruitful endeavors than this.

[Rip Snorter]

If you don't want to trim handgun brass, simply group it by size.  Crimp on all of the mid size range should be perfectly adequate.

[Go West]

If you don't want to trim brass, just use the Lee Factory Crimp die.

[Major Hazzard, SASS #23254]

On 2/13/2024 at 2:40 PM, Buckey O'Neill , SASS Life #42761 said:

Re-loading manuals show a "Max. Case Length", and just below that it lists a "Case Trim Length" which is shorter. Example for .44-40 Winchester:

Max Case Length: 1.305"

Case Trim Length: 1.295"

 

Curious as to why two different case lengths listed.

 

I full-length re-size without expanding the case mouth and then trim my cases to the specified Case Trim Length for new and fired cases.

 

In this case, brass exceeding 1.305" should be trimmed to 1.295".  Keeping brass segregated by lots will help with keeping track of how many times each has been fired.  You'll have to decide for yourself whether one case out of 50 exceeding 1.305" merits trimming the whole lot or not.  For .44-40 brass, ike the fellow above said, use a Lee Factory Crimp die and just never worry about it. 

[Colorado Coffinmaker]

Oh my gosh.  When you've been shooting the same PILE of cases for 20 - 30 years, keeping track of how many time a case has been fired is Oxymoron!!  Not to be SNARKY you understand 

[Go West]

I have two Lyman trimmers I would be happy to sell. 

[Badlands Bob #61228]

The only brass that needs to be trimmed is bottle necked rifle brass.  No need to trim pistol brass.  It will split long before it needs trimming.  

 

Same goes for annealing pistol brass.  Total waste of time.

[Dilli GaHoot Galoot]

5 hours ago, Badlands Bob #61228 said:

The only brass that needs to be trimmed is bottle necked rifle brass.  No need to trim pistol brass.  It will split long before it needs trimming.  

 

Same goes for annealing pistol brass.  Total waste of time.

When I started reloading 45acp I was told by the gunshop I *needed* a case length trimmer, that was in 1980.

I have thousands or cases, some with 1950's head stamps, can't even guess how many times any of it has been loaded, but in all those years I haven't had even ONE case that was long enough for the case trimmer to touch!