7.62x39 Brass to 6.5 Grendel, I know I am noob.

[usmcm16a2]

Folks,


Any pointers? Shoulder on 7.62x39 after being run through FL die, .398, Grendel .425. The case rim on the 7.62x39 just seems a hair wider. Ran through some PPU new 7.62 last night, not much difference in measurements. Put shell in my type 1 barrel from BHW, tried bolt could not twist lugs to lock. Put empty Grendel bolt rotated and lugs locked. This is my barrel not attached to rifle (YET) and the bolt. Any help would be great. A2

[VASCAR2]

I've fireformed two or three different brands of 7.62 X 39 brass without issue. The 6.5 Grendel needs to have the shoulder set back to the proper amount. People have run into problems with not get the shoulder set back far enough due to variations of shell holders and dies. I know with Hornady dies for the 6.5 Grendel it is best to use a Hornady shell holder on a single stage press. Lapua 6.5 Grendel brass tends to be thicker heavier brass than Hornady and I suspect the same is true for 7.62 X 39 Lapua brass. I have to be careful using my Hornady dies when sizing Lapua brass. I have to change my die height for Lapua brass compared to Hornady brass. I have put a crease in the web area of some Lapua brass because my die was down to far. Your wise to check your sized brass in your chamber for fit. If your shell holder is to thick and preventing enough shoulder set back forum members have taken a couple thousandths off their shell holder to get the proper shoulder set back.

When I fireformed my 7.62X39 brass I used a minimum charge of WW 748 and 123 grain A-Max bullets. The actual volume on 7.62 X 39 brass is less than 6.5 Grendel brass by Hornady and Lapua. You can not run the same max charge in FF 7.62 X39 brass as you can 6.5 Grendel brass. The maximum worked up powder charge velocity might still be close with both 7.62X39 and 6.5 Grendel. I have never tested to compare the difference myself. I don't hot rod my reloads in the 6.5 Grendel as modeate velocities with high BC still keeps me on paper for the distances I shoot.

[IceAxe]

I had to take a few thousandths off my RCBS shell holder in order to get it to bump the shoulder on some PMC 7.62 x 39 brass. After that it chambered fine in my BHW barrel.

[Dezynco]

I actually took some off the bottom of my sizing die. It seemed easy enough to square the die up with a sanding disk on my drill press. The shell holder is made from some pretty hard stuff, and is a lot harder to clamp in place. I'm using Hornady dies....I just buzzed a "coat of paint" off the bottom of the die (where the die meets the shell holder).