Thread: 7.62x39 rifling groove diameter

Just an update. I’ve just made up some dummy loads. The .311 neck sizer dis not give enough neck tension. I could push them in by hand😋. .308 neck sizer I could just seat the bullet. The shoulder didn’t seam to deform.

I did notice the .308 collet got pushed up and the last stage of pushing the handle down. Even when I reset the collet and backed the die off a bit. I’m assuming the collect was pushing the bottom of the case.

Dies anyone know why it was doing that?

I may get a gunsmith to shave the .311 collet down to maybe .309 to make seating the projectiles better. I think there should be enough neck tension.
I’m thinking.310 will maybe give to much neck tension.

Thanks for all your advice and help, Brent