Home Forums Hunting & Shooting Ask The Gunwriters concentricity problems caused by seating

With a standard RCBS seating die there's an extra step I do that may help you.

Set the die in the press so the crimp shoulder does not contact the case mouths and lock the die down. Back the seating depth adjustment screw out all the way. Now turn it back in a tiny bit so it's not in a bind.

Now try to seat a bullet. Depending on the bullet it may not even start in the case, or it may start in a little bit. Either way, adjust the seating stem so it starts the bullet into the case a small amount like .04" or .05".

Seat all of the bullets this way.

Once they're all long seated go back and adjust the seating stem to seat the bullets to the desired final overall length.

If your brass isn't plagued with bad necks and you're careful with your technique you may find the runout is cut down a decent amount.