Trimming rifle brass

Discussions covering the components and techniques of reloading for your long gun.
horseman
Supporter
Supporter
Posts: 993
Joined: 09 Nov 2015 06:35
My Press Choice: Single Stage
Location: Washington State
Has thanked: 37 times
Been thanked: 274 times

Trimming rifle brass

Post by horseman »

Trying to figure out how I should go about this. Here's the picture. I was gifted quite a bunch of 06' brass that is "once" fired (?). They appear to me to maybe have been fired from an M1 just looking at the case head. I set my resizing die to just touch the shell holder (co ax) and sized them all. Did check the first few to see if they would chamber in my rifle, a bit stiff but bolt closed, the bolt on this rifle is a bit stiff closing even on an mty chamber so feed back can be somewhat a mystery. Here's my indecision. The case trimmer I'm using spaces off the shoulder to trim, so depending on where the shoulder on the fired case IS in relation to the case head will determine the length. So...if I set up the trim length with a piece of brass that varies in location to the next piece of brass the length will vary between the two by a few thou. shortening the neck more. Think about it for a couple minutes you'll see what I'm talking about. Couple options as I see it, find my old Lee trimmer for 06 and use it and that will take the OAL of the brass to minimum regardless of where the shoulder is OR resize all the brass again and move the shoulder back to a matching point and trim from there with the power trimmer. Once these are fire formed to my chamber it shouldn't be an issue from there. I'm leaning toward the Lee trimmer but I really didn't want to trim to minimum length at this point. I'm gonna think about this for awhile....
User avatar
daboone
Founding Member
Founding Member
Posts: 1397
Joined: 30 Nov 2013 21:47
My Press Choice: Single Stage
Location: AZ, TX, HI
Has thanked: 677 times
Been thanked: 787 times

Re: Trimming rifle brass

Post by daboone »

I always start with "once fired brass" by full length sizing then trim. For the bolt gun I load and shoot some lower pressure rounds for a fun plinking day. Those cases then get neck sized and loaded to my data there after. I'm fond of the Lee's collet dies but sometimes they don't exist, then just the full length sizer back off. Neck sized brass doesn't usually need much of a trim.
Telling you this is like preaching to the choir.
An ignorant person is one who doesn't know what you have just found out.

When setting a job up for myself it must be Idiot Proof as well, as I am a bigger idiot than most people I know, and I prove it to myself everyday.
User avatar
farmerjim
Supporter
Supporter
Posts: 315
Joined: 29 Jan 2015 14:27
My Press Choice: Turret
Location: Saint Francisville LA
Has thanked: 20 times
Been thanked: 114 times

Re: Trimming rifle brass

Post by farmerjim »

Get a 30-06 case length - headspace guage. It will instantly tell you if your headspace and case length are in specs. They are as cheep as $18. Much faster than a caliper and using the rifle chamber. I have them for .223, .308, and 30-06 after a batch (150) 308's did not chamber after sizing and trimming.
horseman
Supporter
Supporter
Posts: 993
Joined: 09 Nov 2015 06:35
My Press Choice: Single Stage
Location: Washington State
Has thanked: 37 times
Been thanked: 274 times

Re: Trimming rifle brass

Post by horseman »

Well I "found" the Lee trimmers that I have and had put in a place I would remember.. :lol: I actually found them while looking for something else I had put "where I would remember"....(have not yet found THAT item) trimmed several pieces and the OAL of the trimmed brass didn't vary more than a thousandth, pretty amazing, I had forgotten how well these worked. PLUS the trimmed length was not to minimum but about half way which was just what I was looking to do. So I think all is well. Not sure why I'm concerned with this process and making a big deal about it, a not so long ago time I would have just set the resizing die to the shell holder plus a bit, resized, trimmed, and loaded without even considering the distance from a datum on the shoulder to case mouth but just OAL of the case. That all changes when these are fired in my rifle anyway.....think I'm chasing something that doesn't matter here as long as the case chambers and the length is in "spec".... :lol: Am I overthinking this..... :geek: ..............yes.
User avatar
Macd
Supporter
Supporter
Posts: 1009
Joined: 16 Oct 2017 16:12
My Press Choice: Single Stage
Location: Far East
Has thanked: 362 times
Been thanked: 403 times

Re: Trimming rifle brass

Post by Macd »

Given the variability of chamber dimensions, even from two rifles of the same model and vintage, and also in sizing dies I prefer the Lee trimmer. Regardless of the shoulder angle or dimensions, the case will always be trimmed from stamp to mouth the same length. Probably doesn't make a lot of difference as long as your case length is no more than SAAMI max.
User avatar
GasGuzzler
Moderator & Supporter
Moderator & Supporter
Posts: 2035
Joined: 26 Jan 2016 22:39
My Press Choice: Turret
Location: Cooke County, TX
Has thanked: 330 times
Been thanked: 500 times

Re: Trimming rifle brass

Post by GasGuzzler »

The Lee trimmer design works well but it is SLOW. Cutters last about 3K pieces of brass and the shell holders loosen up around 5K. Plenty reliable for the price.

I keep my trimmer parts in the corresponding die box.
__________________________________________________________________________________________
I've always been crazy but it's kept me from goin' insane.
horseman
Supporter
Supporter
Posts: 993
Joined: 09 Nov 2015 06:35
My Press Choice: Single Stage
Location: Washington State
Has thanked: 37 times
Been thanked: 274 times

Re: Trimming rifle brass

Post by horseman »

GasGuzzler wrote:The Lee trimmer design works well but it is SLOW. Cutters last about 3K pieces of brass and the shell holders loosen up around 5K. Plenty reliable for the price.

I keep my trimmer parts in the corresponding die box.


I don't find the trimmer slow really. I use it with a cordless drill and that 3 prong chuck thing. Almost as quick as my powered unit. As far as keeping the trimmer parts with the dies, well that just makes to much sense so I'll probably not do that....trying to find them in the "jungle" I call a reloading room gives me something to do on those boring days. And there is usually another plus and that's while looking I generally find something else I forgot I had or had strategically placed to remember where I had put it...... :lol:
User avatar
RBHarter
Founding Member
Founding Member
Posts: 2040
Joined: 13 Mar 2014 19:45
My Press Choice: Single Stage
Location: The green hell 90 miles north of Texarka
Has thanked: 76 times
Been thanked: 670 times

Re: Trimming rifle brass

Post by RBHarter »

I'm a rebel .......I also shoot a few paper patched cast bullets and it's more important there .
I try where brass will be used in only one rifle to trim to that chamber . .002 under chamber length when I can pull it off . It doesn't always work . I have a 45 Colts carbine that has a 1.305 chamber for a maximum case length cartridge at 1.285 that makes a .020 jump from the case mouth to the throat . That's rough in a world where guys are talking .002 off the lands .

06' is a tough one to get longer because there's nothing to stretch the case with short of making a false shoulder step with say a 40 S&W die , FL in the 06' and hope the neck stays put and pulls the body up during the fire form .

Umm the point of my post was full chamber length may be more important for some loads than trim to length .
Just a Red neck,White boy, Blue blood American.....
User avatar
Macd
Supporter
Supporter
Posts: 1009
Joined: 16 Oct 2017 16:12
My Press Choice: Single Stage
Location: Far East
Has thanked: 362 times
Been thanked: 403 times

Re: Trimming rifle brass

Post by Macd »

RB in the previous post makes IMHO an important point regarding knowing your chamber's dimensions if you want to optimize trim length for a specific rifle. My best example is handloading for a 8mm Mauser K98 made in 1944 in BRNO. The chamber is long and loose with an eroded throat. To get this rifle to shoot reliably with any accuracy I have to use oversize cast, mild loads and seat the bullet out as close to the lands as possible.. To accomplish this I reformed 270 Win brass only pushing the shoulder back until it would just chamber in the rifle. The neck was cut back but still long and then trimmed with a Lee trimmer to just under the chamber maximum. The result was a long neck that allowed for a long OAL and the cast bullet to touch and still have adequate neck tension and support. I wouldn't expect to do this for a commercial rifle but the military surplus ones sometimes need you to depart from specs to get them to shoot an acceptable group.
User avatar
RBHarter
Founding Member
Founding Member
Posts: 2040
Joined: 13 Mar 2014 19:45
My Press Choice: Single Stage
Location: The green hell 90 miles north of Texarka
Has thanked: 76 times
Been thanked: 670 times

Re: Trimming rifle brass

Post by RBHarter »

McD brings an interesting point also . While on to another facet still related . As hand loaders we have the option to "fix" head space issues without a machinist . We simply neck up a caliber or 2 and create a false shoulder in some cases it actually makes it an improved or even wildcat cartridge . Of course this is all much easier when you're working a cartridge that is shortened from another . I've had minimal success with stretching cases . Generally a neck down is most useful .
In any case your chamber will trump the book spec . I trim for consistency to a median case length for those that might be used in several rifles and to a specific length for single rifles .
Just a Red neck,White boy, Blue blood American.....
Post Reply

Return to “Rifle Reloading”