How far is your brass growing?

[josh_127]

So I had a rifle built by lri last year...have been working on breaking in the barrel and am now starting load development. I've noticed that my nosler brass moved .014 before it finally head spaced on the shoulder. It took 3 firings to get there at minimum charge loads of data 86 powder (cool flame temp) for breaking it in gently on the throat...(ran 65 grains with 180 sierra mk @2750 fps) I know it took three shots to get my brass to full length because of the mild loads but is it typical for nosler brass to be that much shorter than a saami spec chamber?

 

[Lefty7mmstw]

Sometimes, yes. I've got issues with brass growth with my rifle. I've got 100's of spare cases but won't sell any because I've seen case separation in just a few firings in my chamber. I just reset my dies for partial fl to slow this down. I don't really like partial sizing as it doesn't close the die and square things up, but I'm not going to neck sizing on a hunting rifle.
On the flip side, my 338win in a Ruger #1 in growing .003" per firing and my kid's 6.5 creed is growing that or less... It's nice when range find brass lasts forever and stuff you drop a couple $ a hull on fails in 3

 

[Coyote Shadow Tracker]

So I had a rifle built by lri last year...have been working on breaking in the barrel and am now starting load development. I've noticed that my nosler brass moved .014 before it finally head spaced on the shoulder. It took 3 firings to get there at minimum charge loads of data 86 powder (cool flame temp) for breaking it in gently on the throat...(ran 65 grains with 180 sierra mk @2750 fps) I know it took three shots to get my brass to full length because of the mild loads but is it typical for nosler brass to be that much shorter than a saami spec chamber?

We use many brass espically Labua, but we used Nosler Brass and Nosler cuts their brass short so you can get many loading brfore you need to trim. I usally soak my nosler Brass in Nitrogen/postassum with water, after about two day the breass has grown to full length and I can the trim down along withchampering the inside and outside of the mouth of the brass.

 

[can1010]

you didnt say but it sounds like your shooting a 300 win mag. brass being that short is very common with all belted mag cases of all manufactures, Peterson is the only company to address this issue with there 300 win mag long brass which is longer to the datum line than all others and I have had to size new brass to set shoulder bump before the first firing.

 

[josh_127]

7mm stw...my 300 win gets fed peterson long.....002 short of heads pace right out of box.

 

[lancetkenyon]

Except for Peterson .300WM Long brass, every single virgin belted mag case I have shot (.264WM, 7RM, 7STW, .300WM, .338WM etc.), regardless of manufacturer, has been between .014-.021" short on headspace to the shoulder. For the life of me, I still can't figure out why they do that.

 

[kfreeze]

So I had a rifle built by lri last year...have been working on breaking in the barrel and am now starting load development. I've noticed that my nosler brass moved .014 before it finally head spaced on the shoulder. It took 3 firings to get there at minimum charge loads of data 86 powder (cool flame temp) for breaking it in gently on the throat...(ran 65 grains with 180 sierra mk @2750 fps) I know it took three shots to get my brass to full length because of the mild loads but is it typical for nosler brass to be that much shorter than a saami spec chamber?

.014 isn't growing that much for a belted mag round. If it worries you, you can always jam the lands and run a decent load to blow the brass out without stretching it at the web.

 

[nksmfamjp]

If I thought I was going to get 0.014" growth, I would COW form with a false shoulder. That is a lot!

 

[josh_127]

I've been debating trying cow method...I've never done it. I do have a 6-250 ai that'd be handy for and this stw.

 

[Bob Wright]

Except for Peterson .300WM Long brass, every single virgin belted mag case I have shot (.264WM, 7RM, 7STW, .300WM, .338WM etc.), regardless of manufacturer, has been between .014-.021" short on headspace to the shoulder. For the life of me, I still can't figure out why they do that.

The parent brass design was a "dangerous game round", by which it was guaranteed to chamber in the rifles and doing so off the belt, not the shoulders. Mine grew .019 after 2 firings and a final anneal.

 

[spladi]

So I had a rifle built by lri last year...have been working on breaking in the barrel and am now starting load development. I've noticed that my nosler brass moved .014 before it finally head spaced on the shoulder. It took 3 firings to get there at minimum charge loads of data 86 powder (cool flame temp) for breaking it in gently on the throat...(ran 65 grains with 180 sierra mk @2750 fps) I know it took three shots to get my brass to full length because of the mild loads but is it typical for nosler brass to be that much shorter than a saami spec chamber?

Belted case? then yes

 

[nksmfamjp]

I've been debating trying cow method...I've never done it. I do have a 6-250 ai that'd be handy for and this stw.

COW Fireforming recipe

I thought I posted this somewhere else, but I did not. First: The formal instructions https://bulletin.accurateshooter.com/2017/02/how-to-fire-form-brass-without-bullets/ Found this reference for starting charge weight...

www.longrangehunting.com

 

[WapitiBob]

Nosler brass, 7stw, first firing moves shoulder 17-18 thou, and doesn't touch the chamber wall. It'll take two firings to get it sized. 80.5gr RL25 3470 fps.

 

[Lefty7mmstw]

Nosler brass, 7stw, first firing moves shoulder 17-18 thou, and doesn't touch the chamber wall. It'll take two firings to get it sized. 80.5gr RL25 3470fps.

Thanks for the info on the Nosler 7stw brass Bob. I picked up some locally last fall for an absolute song and it's been in reserve. I'll probably just do a false shoulder and blow it out when it's time to use it. I've had a similar issue with Bertram 7stw and it was irritation with second firing head separation on a few cases.
It's kinda funny how every 7stw reacts differently to rl25. I'm using 82 rl24 in rp brass with a 140 ab and clocking high 3300's, like 3360-3375... You are faster with less powder; what grain weight for bullet again if I may ask?