Originally Posted by robert6715
I am pretty sure that belted magnums headspace off the belt.
I understand the idea of just barely bumping the shoulder to keep the case from growing. I do this with my 338-378. In essence you are getting the round to headspace off the shoulder like a non-belted round.
If he has a FL die set to "cam over" and the die is made to spec, then he is surely headspacing off the belt.
...and they do (but I have none), all mine headspace off the shoulder. Having said that and looking at the latest pictures, I'd say there is a headspace issue but not a shoulder headspace, rather a headspace issue with where the belt locates in the chamber.
I'm not at all sure if you can alter the headspace on a belted magnum by altering the relationship between the closed shellholder position and/or the die base because again, I don't have or load any.
I believe I'd be taking it back to the builder with some hard questions (and a smoked case in hand).
I'm curious about the accuracy and how the pills group.
Theoritically, if the cartridge was headspacing (beltspacing in this case) too far out, that would allow the combustion gases to leak around the case and cause what the pictures show. I would assume that it would also cause inconsistent groupings.
Again, not familiar with any belted magnums, I don't own any and don't reload any and I apologize for leading anyone down the wrong path.