Sorting GFL Cases by length, to determine if a trimmer is needed.

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Sorting GFL Cases by length, to determine if a trimmer is needed.

Post by mikemyers on Sat Apr 21, 2018 9:28 pm

Reloading for S&W Model 52:

I was looking at LenV's image of several finished bullets, paying attention to the crimp.  It's hard to tell in the photo, but one of them looked it had more crimp than another.  I need to re-adjust my seater die, and I want to copy as much as possible what his rounds look like.

I was wondering if I need to start trimming case length.  I have probably 200 GFL 38mm brass cases.  I did this comparison only for GFL, but I also have Winchester cases.  I might check those later.  

I measured the length of fifty cases at random with a digital caliper.
shortest case was 1.137. Next shortest was 1.140
longest case was 1.155.  Next longest was 1.153

Average case length was 1.145

Difference between shortest and longest was 0.018 inches


A few questions.

  • What is the optimal case length for the S&W Model 52?
  • With a possible 0.018 difference in length, if I don't trim the cases, can I still use a Roll Crimp?
  • Is it worthwhile to not use the crimper in my seater/crimper die, and crimp in another operation on a different press?
  • Last, is two hundredths of an inch that critical, that I even need to worry about this?


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Re: Sorting GFL Cases by length, to determine if a trimmer is needed.

Post by dronning on Sat Apr 21, 2018 9:51 pm

I'll answer your last question, no. 
- Dave
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Re: Sorting GFL Cases by length, to determine if a trimmer is needed.

Post by john bickar on Sat Apr 21, 2018 10:54 pm

dronning wrote:I'll answer your last question, no. 
- Dave
Better off working on 9 inches of headspace and 1/4” of trigger finger movement.
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Re: Sorting GFL Cases by length, to determine if a trimmer is needed.

Post by mikemyers on Sat Apr 21, 2018 11:23 pm

john bickar wrote:
dronning wrote:I'll answer your last question, no. 
- Dave
Better off working on 9 inches of headspace ......
I'm lost.   Headspace?  How does one get 9 inches of it with a handgun?    :-)
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Re: Sorting GFL Cases by length, to determine if a trimmer is needed.

Post by LenV on Sat Apr 21, 2018 11:39 pm

Yep, your lost. Laughing OHS common problem with all aspects of shooting and life. It is also the number one reason that remote controls don't work.
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Re: Sorting GFL Cases by length, to determine if a trimmer is needed.

Post by Wobbley on Sat Apr 21, 2018 11:47 pm

The real answer is in your head. If you think not sorting brass for length harms your shooting it will. Rather than trim I’d segregate at 1.146 and above in one batch, below that in another. Brass being what it is, you’ll have to re-measure each reload. But that’s the extent. You’ll likely find that it will make no difference but there it is.
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Re: Sorting GFL Cases by length, to determine if a trimmer is needed.

Post by Jack H on Sat Apr 21, 2018 11:58 pm

This isn't benchrest shooting.  But if you must, set your crimp on a case in the middle of your heaviest distribution within your sample.
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Re: Sorting GFL Cases by length, to determine if a trimmer is needed.

Post by LenV on Sun Apr 22, 2018 12:25 am

Not for a 52 but current and applicable. Today I shot a 2700 in Sherwood, OR. A friend/fellow shooter was picking up brass off the floor that missed our nets and asked what I was shooting. My honest answer was "everything". I decided to clean house and I was shooting every oddball weird headstamp in my inventory. I even pointed it out to Him once when I had two in the same magazine with the same headstamp. Believe me they were not sorted by weight, length or even coating. Brass and nickel ,GFI and Blazer (and about 20 more) it made no difference. They all got fired. Didn't seem to effect accuracy. Or function. Zero alibis.



Actually it was closer to about 30 more.


Last edited by LenV on Tue Apr 24, 2018 6:39 pm; edited 1 time in total (Reason for editing : added picture of head stamps shot Saturday)
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Re: Sorting GFL Cases by length, to determine if a trimmer is needed.

Post by fpk on Sun Apr 22, 2018 1:26 am

1.140 is supposed to be the optimum length for 38 special in a Model 52. I trim because I want to eliminate the variable, but as others have said it probably doesn't matter except for X count.

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Re: Sorting GFL Cases by length, to determine if a trimmer is needed.

Post by mikemyers on Sun Apr 22, 2018 8:07 am

Wobbley wrote:The real answer is in your head.  If you think not sorting brass for length harms your shooting it will.  Rather than trim I’d segregate at 1.146 and above in one batch, below that in another.  Brass being what it is, you’ll have to re-measure each reload.  But that’s the extent.  You’ll likely find that it will make no difference but there it is.
Actually, I didn't have any answer - I keep reading about this stuff, so I wanted to measure 50 or 100 rounds, just to find out how much variation I had. I had no idea what to expect, and I was surprised how little variation I found.

I'd like to think that the only thing that harms my shooting is my level of ability.  Following what you guys discuss and answer helps me improve my ability, in so many ways.  I'm sure a barrel filled with lead crud made some kind of difference - by next weekend, maybe sooner, the barrel will be clean.  I read where a poor crimp can create problems, but it didn't seem worthwhile to work on that until I knew if I had a problem from case length.  Case length is now off my list, but I need to figure out which type of crimp to use, and get my die set accordingly.  I keep remembering that Gil Hebard wrote that poor reloading can make a 7" difference in group size, so to my way of thinking, that's pretty high on my list.  I should get out my book and quote him exactly - I think he wrote 15" at 50 yards, so I cut it in half for 25.


LenV, I'm even more lost than you think I'm lost.  Eventually I may figure out what you meant by:  "Yep, your lost.  OHS common problem with all aspects of shooting and life. It is also the number one reason that remote controls don't work."

OHS?  Remote Controls?  I'm thoroughly confusabobbled.  But I've learned to live with confusabobbleability.  Just do the best I can, anyway.
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Re: Sorting GFL Cases by length, to determine if a trimmer is needed.

Post by LenV on Sun Apr 22, 2018 12:01 pm

Sorry Mike. To end the confusion OHS stands for Operator Head Space. I.E. The space between the ears. I guess I was in the military too long. Common acronym.

Len
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Re: Sorting GFL Cases by length, to determine if a trimmer is needed.

Post by mikemyers on Sun Apr 22, 2018 12:32 pm

That's OK, it's like me telling people the most important part of a camera is what's twelve inches behind the camera.

Don't be sorry - now I have one more term that I can use to further confuse people.   :-)   



Besides, if it wasn't for you, I wouldn't have started to read this:
https://en.wikipedia.org/wiki/Headspace_(firearms)
There's always good stuff to read and learn and think about, just from participating in this forum!
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Re: Sorting GFL Cases by length, to determine if a trimmer is needed.

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