No need to trim

[AmishEskimoNinja]

The last few times I've gone to reload my brass I've have the pleasant surprise that I didn't need to trim it. I'm using Lapua brass FL sized and trimmed as unfired brass, then after several more firings in my AR15 and several more FL resizings I'm still well under the max case length. The cases measured 1.502-1.510. Anyone else have this experience?

Here's my setup:
Hornady LnL press
Hornady custom grade dies
Lapua brass trimmed to 1.506 originally
LE Wilson case gauge

[bwaites]

I've never trimmed a piece of Lapua brass and I have 20+ reloads on some of my oldest.

[lamrith]

Bwaites, did you trim on 1st use at all? If not I am curious what the length was new, maybe it was at minimum length so room to stretch before needing trimming?

[bwaites]

Bwaites, did you trim on 1st use at all? If not I am curious what the length was new, maybe it was at minimum length so room to stretch before needing trimming?

About half my brass is from factory loads, about half is new. When I first started reloading it, I called Bill Alexander and asked about full length resizing or trimming new brass. He told me to load and shoot new brass, running a ball through any that looked like they had been dinged in the case mouth. No need to measure it, no need to trim it, no need to resize it. Just for curiosity, I checked a few for case length and found they were all actually at or slightly (001.003) below minimum case length when new. Over the last 8-10 years I've talked to lots of shooters who use Lapua brass in other calibers, and every one has said that Lapua brass is always undersized when brand new, it doesn't matter what caliber. After one firing it is chamber sized and they go from there.

I know that I have never trimmed any, and I don't believe I've ever heard LR1955 ever mention trimming Lapua brass either and he's the only guy on forum who has shot more of it than me, I think. (stokesrj has too, but he is seldom around anymore!)

[LR1955]

About half my brass is from factory loads, about half is new. When I first started reloading it, I called Bill Alexander and asked about full length resizing or trimming new brass. He told me to load and shoot new brass, running a ball through any that looked like they had been dinged in the case mouth. No need to measure it, no need to trim it, no need to resize it. Just for curiosity, I checked a few for case length and found they were all actually at or slightly (001.003) below minimum case length when new. Over the last 8-10 years I've talked to lots of shooters who use Lapua brass in other calibers, and every one has said that Lapua brass is always undersized when brand new, it doesn't matter what caliber. After one firing it is chamber sized and they go from there.

I know that I have never trimmed any, and I don't believe I've ever heard LR1955 ever mention trimming Lapua brass either and he's the only guy on forum who has shot more of it than me, I think. (stokesrj has too, but he is seldom around anymore!)

Guys:

I think I trimmed some after over 20 firings. This was because I had fired different lots of Lapua brass from different chambers and just wanted to get things even again. Nothing was over max length. I didn't need to trim them.

Neck turning and annealing brass is also a unnecessary waste of time. Both do more damage to the brass than good.

LR55

[Savage Shooter]

I have an AA 24" upper and I was trying to figure out trim-to dimensions. I wrote the following to Bill Alexander: "The Reloading Information page for your site states a trim-to length of 1.520" with a 1.526" MAX, Hornady's manual states 1.506/1.516, Berger's Manual has 1.504 trim, Hogdon has 1.515 and Nosler 1.520. My actual fired cases from Hornady factory ammo ranged from 1.512 to 1.520 before resizing - I am not sure if I should trim or not?"

This was his response: "The chamber dimension allows for the case to run to a maximum above 1.526" so the trim may be shorter and as long as it is consistent then the exact value is not important. The ability to measure exactly, on a brass case which is subject to expansion due to heat, is always in question. Bullet pull or uncork pressure is the dominant factor in behavior of a round of ammunition."

So, depending which source you want to believe and your own chamber dimensions, your trim-to length could be substantially longer than what you are up to now. But, as LR1955 stated, which goes along with what Bill advised, consistency of length for accuracy is possibly going to be the determining factor in when to trim, and like others you might never reach your chamber's MAX trim length.

[Bwild97]

I have always trimmed Hornady brass (1.518, some needed it some didn't) never have I had a Lapua (AA) case need trimming. I use a Giraud's trimmer on all my brass, as I said some need it some don't, but evey piece goes through the Giraud.

[rasp65]

I measured my chamber length at 1.540". In my case they will not need to be trimmed as much as evened up.

[motoxxx_ryder]

for trim length books are only manufacturers spec. I load alot for precision so i like to know as much about my chamber as possible. The best tool to find trim length is the sinclair chamber length gauge. Simply cut a peice of brass short and insert the tool, drop it in the chamber and close the bolt then measure. Personally i do this 3-5 times. if i get the exact same number 3 times i'm good, if its off by .002 or more ill check 5 times and usually get 3 that line up.

write this number done in your data book (you have one for either reloading or one for each rifle right?) as your maximum case length. You can either shoot it until it gets to this length then trim .01 or trim to any consistent length under that.

http://www.sinclairintl.com/reloading-equipment/measuring-tools/case-gauges-headspace-tools/sinclair-chamber-length-gage-sinclair-chamber-length-gage-6-5-mm-sku749-000-783-32925-64795.aspx

AS far as lapua brass, so far i run it on my 338 308 and my 223 the 338 needed to be trimmed after 6 shots. 223 and 308 are 3 shots and no need yet.

[Savage Shooter]

The best tool to find trim length is the sinclair chamber length gauge.

http://www.sinclairintl.com/reloading-equipment/measuring-tools/case-gauges-headspace-tools/sinclair-chamber-length-gage-sinclair-chamber-length-gage-6-5-mm-sku749-000-783-32925-64795.aspx

They don't recommend use in a semi-auto (or lever or pump), I am guessing because there might not be enough force to be sure the bolt is fully closed and the insert driven in completely, hence you'd get an inaccurate chamber length reading (too long) and if you loaded a live round to that length, get yourself in real trouble. So, if you did use the tool for a semi-auto, better be sure to subtract an extra 0.01 or so (or more if your measurement is significantly over recommended max in your reloading manuals.)

For those reloaders who take the extra step to neck turn their brass to control tension, the extra bearing surface of an even longer neck, IF NOT TRIMMED TO A UNIFORM length, will likely increase the variability in release tension and be counter-productive to what they are trying to achieve by neck turning in the first place. That said, in a semi-auto Grendel shooting around 1 MOA, all the more advanced "bench-rest" reloading techniques (weight sorting bullets and cases, sorting by bullet bearing surface length, neck turning, weighing powder to +/- 0.05 gr, etc.) are probably over-kill, and I am trying to convince myself to skip them and spend more time shooting and practicing and less time measuring.

[terrywick4]

[QUOTE=bwaites;108666]About half my brass is from factory loads, about half is new. When I first started reloading it, I called Bill Alexander and asked about full length resizing or trimming new brass. He told me to load and shoot new brass, running a ball through any that looked like they had been dinged in the case mouth. No need to measure it, no need to trim it, no need to resize it. Just for curiosity, I checked a few for case length and found they were all actually at or slightly (001.003) below minimum case length when new. Over the last 8-10 years I've talked to lots of shooters who use Lapua brass in other calibers, and every one has said that Lapua brass is always undersized when brand new, it doesn't matter what caliber. After one firing it is chamber sized and they go from there.

I know that I have never trimmed any, and I don't believe I've ever heard LR1955 ever mention trimming Lapua brass either and he's the only guy on forum who has shot more of it than me, I think. (stokesrj has too, but he is seldom around anymore!)[quote]

So you just pop the primer out and don't size anything? Aren't the bullets loose in neck?

[terrywick4]

So you do not size anything? Just pop the primer, put a new on in, dump some powder, put a bullet in? Aren't the bullets loose in the neck?

About half my brass is from factory loads, about half is new. When I first started reloading it, I called Bill Alexander and asked about full length resizing or trimming new brass. He told me to load and shoot new brass, running a ball through any that looked like they had been dinged in the case mouth. No need to measure it, no need to trim it, no need to resize it. Just for curiosity, I checked a few for case length and found they were all actually at or slightly (001.003) below minimum case length when new. Over the last 8-10 years I've talked to lots of shooters who use Lapua brass in other calibers, and every one has said that Lapua brass is always undersized when brand new, it doesn't matter what caliber. After one firing it is chamber sized and they go from there.

I know that I have never trimmed any, and I don't believe I've ever heard LR1955 ever mention trimming Lapua brass either and he's the only guy on forum who has shot more of it than me, I think. (stokesrj has too, but he is seldom around anymore!)

[NugginFutz]

So you do not size anything? Just pop the primer, put a new on in, dump some powder, put a bullet in? Aren't the bullets loose in the neck?

He was referring specifically to new brass.

[terrywick4]

makes more sense now that I read it ALL this time.

[bwaites]

makes more sense now that i read it all this time.

lol!