I just recently purchased a 7mm Rem Mag and have heard many different ways to resize the cases and was wanting to know how your best luck.
Yes! one reason would be a belted case that is shorter the then minimum SAAMI standard dimensioning tolerances. This is the reason you can not just blow off the factor behind a specific case design. A belted case is designed to have headspace controlled by the belt not the base to datum length. You can ruin a belted case the first time they're fired. How much did that specific belted case have to stretch to headspace on the case shoulder? What is the base to datum length of new brass in comparing to once-fired brass from your particular rifle chamber? How much will the case have to stretch to headspace on the shoulder? The dimensioning & tolerances of the die, brass case, and particular rifle chamber are all based on SAAMI specifications that work off the fact that with a belted case headspace is controlled by the case belt. The problem is case stretch how much and how many times! Wish you all the best LaneHipshot said:Interesting points, Lane. Is there any reason that a belted bottleneck case cannot headspace off the shoulder rather than the belt?