When to trim??

[Gunneegoogoo]

The first in my series of tonight's 2 rookie questions:

As of right now all of my brass is under SAAMI specs for length.

Do I need to trim to make everything exactly the same, or wait until they start to creep past the specs?

Thx.

-J.

 

[captainmike]

I trim every 3 firing when my brass approach the max length exemple for my 308 max is 2.015 so when I
mesure the brass and have a few around 2.012/2.013 I trim the all batch @ 2.005

 

[PitBull1973]

The first in my series of tonight's 2 rookie questions:

As of right now all of my brass is under SAAMI specs for length.

Do I need to trim to make everything exactly the same, or wait until they start to creep past the specs?

Thx.

-J.

Is your brass once fired to your chamber. If it's new and unfired I would shoot them first then bump the shoulder back then trim.

 

[cycbb486]

My routine that rolls over from the Bench Rest world is trimming after every firing.... For my competition rifles I use a Homer Strickland trimmer and for my others they are done on the Wilson...

Whatever tickles your fancy.....

 

[coltseries70]

I trim when it gets caught in my fly.

 

[MuthaFunk]

I trim when it gets caught in my fly.

Boooo!

 

[silverfoxdj]

I only trim when going over the max length

 

[Magellann]

I trim when it gets caught in my fly.

 

[silverfoxdj]

I trim when it gets caught in my fly.

Oooooh!!!!

 

[hometownhero]

I measure and if it is over or a few thousandths away from max I trim them back.

 

[Eagleye]

When any case in a given batch reaches max SAAMI length, I trim them all.

Some cases "grow" faster than others, which simply means some will need trimming at 3-4 firings,
whereas others may go 8-10 firings without a trim.
Regardless, I usually anneal every 4-5 firings.

Case design has a definite influence on case growth, very "hot" loads can cause more growth.
Also a tight or sticky expander ball in a die can accelerate lengthening of a case.
I lube necks inside with powdered graphite to keep this at a minimum.

If your cases seem to grow in length too quickly, watch for incipient case separations.
It is possible you may be setting the shoulder back too much when you FL size.

Regards, Dave.


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[Gunneegoogoo]

Is your brass once fired to your chamber. If it's new and unfired I would shoot them first then bump the shoulder back then trim.

Most is once fired for my .338 and 6.5. My .308 will be brand new (chamber and brass) so I'll do just that.

Is their a "magic number" under spec to go? .003??

 

[Gunneegoogoo]

Thank you all so far.

The "in my fly" comment........hahahahahhahahahah!!!!

 

[Eagleye]

Most is once fired for my .338 and 6.5. My .308 will be brand new (chamber and brass) so I'll do just that.

Is their a "magic number" under spec to go? .003??

I trim to .010" under SAAMI max length. Dave.

 

[Qball-16]

Most is once fired for my .338 and 6.5. My .308 will be brand new (chamber and brass) so I'll do just that.

Is their a "magic number" under spec to go? .003??

My Hornady manual, and the Hodgdon Reloading website both list a 'trim to' length for brass. For example, with my .223, max length (SAAMI) is 1.760" and the 'trim to' length is 1.750".

For me, I have a Forster lathe-style trimmer, with their 3-in-1 cutter head (trims, chamfers & de-burrs at the same time) so I knock them all back to 1.750" every time. For some, it barely trims at all, but enough for the chamfer/de-burr.

 

[mmcintyre1220]

I trim when it gets caught in my fly.

LMFAO !!! Thank you I needed that laugh

 

[Gunneegoogoo]

I have the WTF2. I've read good and a bit of bad on them. I'll see how they do for me.......

 

[silver 55]

There is some good advice on here. What I do is keep an eye on my brass/reloading setup. I had one cartridge that needed to be trimmed practically every reload. So I started measuring almost everything. Turned out a freshly sized brass would come out about .008 or .009 longer than it went in. I bought a neck sizer for that one.

I did learn something on here last summer. I had a rifle/cartridge combination that had given me some very good groups but lately was slipping. I measured the outside of the neck of the brass and got some interesting results. The very end of the brass and even part way up was consistant but right next to the shoulder was .003 to .005 larger. I outside neck turned my brass and the group size got a lot better.

I would suggest at 10 or 15 or even 20 reloads that you measure the outside neck diameter. If it is growing near the shoulder, trim it. Compare the groups of the trimmed brass to the untrimmed.

Come to think of it, I will measure outside neck diameter every time I trim for length.

 

[Gunneegoogoo]

There is some good advice on here. What I do is keep an eye on my brass/reloading setup. I had one cartridge that needed to be trimmed practically every reload. So I started measuring almost everything. Turned out a freshly sized brass would come out about .008 or .009 longer than it went in. I bought a neck sizer for that one.

I did learn something on here last summer. I had a rifle/cartridge combination that had given me some very good groups but lately was slipping. I measured the outside of the neck of the brass and got some interesting results. The very end of the brass and even part way up was consistant but right next to the shoulder was .003 to .005 larger. I outside neck turned my brass and the group size got a lot better.

I would suggest at 10 or 15 or even 20 reloads that you measure the outside neck diameter. If it is growing near the shoulder, trim it. Compare the groups of the trimmed brass to the untrimmed.

Come to think of it, I will measure outside neck diameter every time I trim for length.

I think what you are describing is "donut" formation (I think). Are you using a bushing sizing die??

-J.

 

[silver 55]

I think what you are describing is "donut" formation (I think). Are you using a bushing sizing die??

-J.

I don't think so, it is just a redding neck sizing die.