Thread: Full length resizing 7mm Rem Mag problem

I agree with @grandpamac
Back the sizing die out a bit. Set it so its hardly touching the shoulder.

Its generally thought that best practice when sizing belted magnums is to neck size only. This causes the fired cases to headspace off the shoulder and not the belt. (you can do it will a full length sizing die, or a specific neck sizing die)
So basically you want to be resizing it as little as possible. Enough that it will chamber correctly and that the neck can hold a projectile properly and no more.

Can you wind the die out a bit and still have it chamber OK? If so - do that. Keep winding it out so that it sizes the whole neck but doesn't really touch the shoulder. Or you can use a neck size only die.