Making up the Type I vs Type II difference by fire forming

[Chrazy-Chris]

Long story short, I've been using a type II bolt with a type I barrel for years and finally started seeing case head separation. The brass lasted at least six firings even with all that extra forming. Basically I've just been resizing my brass more than necessary until it finally started to give.

SO that brings me to my plan which I am seeking feedback on. Rather than switch bolts to a crap brand 7.62x39 I have laying around, I'd like to simply resize the brass less. I know I can measure off the shoulder and just bump it back a few thou; just not sure if I'm opening to other issues. I will have slightly more powder capacity which is neat, but not sure if it'll be noticeable. Especially since I'll still be restricted to mag length.

Really hoping that addressing this discovery tightens up my groups. It's been roughly a 1moa rifle and very picky with reloads.

[1Shot]

Here is a quick fix for both or your problems, type 1 chamber and accuracy. For under $170 you can get a Group Buy barrel and replace your barrel. Problem solved.

[VASCAR2]

At $.50 to $1.00 for each piece of 6.5 Grendel brass I’d either use a 7.62x39 bolt or buy a .136 chambered SAAMI spec barrel. There are enough hazards in shooting to knowingly use mismatched parts. Having been around firearms when they blew up (not mine) I try to stay within safe parameters. If you use a x39 bolt and keep pressures reasonable it’d probably be cheaper to use the x39 bolt and get longer life out of the brass.

If the barrel has a short chamber and your trying to use a .136 bolt then I’d either ream the chamber or cut my losses and just get a new barrel.

I’m with 1Shot on this one!

[grayfox]

+1, don't play around with your face, eyes, etc..... barrels are cheap, eyes are not.
Keep everything in spec. Just because you dodged a bullet -- so to speak -- don't continue to play those odds.
The "house" (Murphy's house) is gonna win on ya that way for sure!!!