300 Win Mag brass

TackDriver284

Handloader
Feb 13, 2016
1,801
481
My current Norma brass for the 300 Mag has been fired at least 4 to 5 times, and on the last loading I did feel some slightly loose primer pockets. I'm lurking around for better brass if any, what do you guys think about Petersons or Lapua brass? I have had great results with Lapua brass in smaller calibers.
 

jimbires

Handloader
Aug 16, 2011
2,496
459
take a look at Peterson 300 win mag "long" this should help the brass last longer . I think Peterson is the only brand that offers long .
I have no complaints on any Lapua brass I've used .
 

TackDriver284

Handloader
Feb 13, 2016
1,801
481
take a look at Peterson 300 win mag "long" this should help the brass last longer . I think Peterson is the only brand that offers long .
I have no complaints on any Lapua brass I've used .
Yes, I looked at Petersons last night and a You Tube video about the 300 Win Mag long brass, and I understood why they made it as " long " and I wanted to get that brass but its out of stock, so I purchased 100 pieces of Lapua from Graf & Sons which was cheaper than Midway. I haven't had no issues with Lapua brass either, I used Lapua in all of my rifles except 7mm Mag and the 300 Mag. Lapua started making brass again for the 300 Win Mag last year I think.
 

TackDriver284

Handloader
Feb 13, 2016
1,801
481
Tough to beat Lapua brass. It's expensive but with the longer life, it's probably cheaper in the long run.

JD338
Yes, lasts a long time, I think I ran the 308 Lapua brass 20 times already, annealed after each firing and keeps on ticking. Primer pockets are still snug.
 

SJB358

Ballistician
Dec 24, 2006
31,355
656
RWS, Lapua and ADG would be my pick. I can strongly vouch for ADG (brothers) and RWS (Me and Mashburn). I put Lapua in there cause they don’t ever make crap that isn’t near or at the top.
 

SJB358

Ballistician
Dec 24, 2006
31,355
656
Tough to beat Lapua brass. It's expensive but with the longer life, it's probably cheaper in the long run.

JD338
I used to think great brass was expensive till I started getting 10+ and more firings with it and in some of the rifles 20+. To me once they are shot the first time and prepped I wanna keep them as long as I can.
 

jimbires

Handloader
Aug 16, 2011
2,496
459
I can never use my brass evenly . I get the number of cycles out of sync all the time . this batch of 50 have 10 - 13 reload cycles on them . I'm going to junk them after the 13 fire . I'm pretty sure I had case head separations at 15 cycles , on my previous brass . this brass is run hard . you can see ejector marks . I have no problems with short case life or loose pockets . this shows the value of top shelf brass .

P2180256.JPG
 

RL338

Handloader
Mar 23, 2017
783
705
As stated by others Lapua is darn good brass.
13 firings on a belted case is pretty darn good.
 

jimbires

Handloader
Aug 16, 2011
2,496
459
those are not belted , they are 338 lapua .


I think the initial fire on belted brass causes short case life . that first fire can cause brass to stretch .015" or more . that's why I suggested the peterson long .
 

TackDriver284

Handloader
Feb 13, 2016
1,801
481
The Lapua 300 Win Mag brass just came in,,,,I got bored so I did some measuring. I decapped three fired Norma 300 brass and measured the headspace and it measured 2.275" and I measured three pieces of Lapua 300 brass out of the box, no sizing at all, and two pieces measures 2.260" while the 3rd piece measures 2.262". That is .013" and .015" difference from unfired and fired. I'll size the new brass later to see if they change dimensions, but I doubt much change will happen. After firing, I always minimize my bumps to .0015 to .002" to prolong brass life. Next time I'll get the Long when they are in stock. The picture is from You Tube, it shows the headspace length of the Long unfired compared to the other unfired and fired cases. Nice stuff.

ecIACzi.jpg
 

SJB358

Ballistician
Dec 24, 2006
31,355
656
The Lapua 300 Win Mag brass just came in,,,,I got bored so I did some measuring. I decapped three fired Norma 300 brass and measured the headspace and it measured 2.275" and I measured three pieces of Lapua 300 brass out of the box, no sizing at all, and two pieces measures 2.260" while the 3rd piece measures 2.262". That is .013" and .015" difference from unfired and fired. I'll size the new brass later to see if they change dimensions, but I doubt much change will happen. After firing, I always minimize my bumps to .0015 to .002" to prolong brass life. Next time I'll get the Long when they are in stock. The picture is from You Tube, it shows the headspace length of the Long unfired compared to the other unfired and fired cases. Nice stuff.

ecIACzi.jpg

On first firing on new brass, I neck up 1 caliber with an expander mandrel. So a 300 Win would get necked to to .323 since that is what I have. Then I size the neck until it JUST chambers on my rifle. That false shoulder that is created will minimize the initial stretch since the case fits snug in my chambers and blows outwards instead of having to grow from the base.

Like Jim mentioned, my case life is near forever. If my primers stay snug and the cases are annealed then I continue to run them.
 

jimbires

Handloader
Aug 16, 2011
2,496
459
I thought that would help this short virgin brass problem . I've never done the false shoulder thing , but I understand it . do you anneal after forming the false shoulder , before the first fire ?
 

SJB358

Ballistician
Dec 24, 2006
31,355
656
If it’s brand new brass I don’t anneal till after firing Jim.

One caliber up doesn’t seem like a big deal mostly. It’s really a slight bulge just to get a solid headspace on first firing.
 

jimbires

Handloader
Aug 16, 2011
2,496
459
thanks Scotty , that's what I thought .


Fellas , this false shoulder trick works on any bottle neck cartridge , not just belted cases . if you have a generous chamber , that leads to short brass life from case head separation, this sure would be worth a try .
 

NYDAN

Handloader
Sep 17, 2013
1,254
237
Guys, this is a great discussion. I had also found that the shoulder reference point (head space) on new belted brass was up to .017" short. I had remembered reading about making a false shoulder, but I couldn't remember how. I will be starting to load 300 WM this spring and I was hoping I would run across it somewhere. This discussion is very timely for me. Since I have to order an expander just for this is, there a better size then the 8mm to use. Weren't there some cartridges that ran .311 or .312 size bullets? Maybe that is not enough to create the false shoulder.

Dan
 
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