I have a project going currently using the Magtech 16ga. I'm wrapping tape around the mouth and just in front of the rim. When fire formed it will form the case in the middle and still be concentric to the centerline of the case/bore. after the first fire form I will remove the tape and do it again. I read an article that described something similar and then talked to a friend who had done it this way. I'm going to try to shoot a turkey with my 14ga and season opens in a couple weeks, so i should have some results to report soon.
Bryndon
