Originally Posted by RTK
I will do some experimenting with FL sizing on the 300wm in the next few months to see. I'm not too proud or too smart to try something new and learn.
Good idea. Here's some info I'll pass on based on reloaders experience with belted cases beginning in the late 1950's when really good 30 caliber match bullets were finally available from Sierra Bullets.
Top long range competitors shooting 30 caliber magnums learned that new cases shot more accurate than any sizing method on fired cases produced. The problem was the tiny ridge right in front of the belt caused by the case body expanding between the belt and the ridge in the chamber a few thousandths in front of it. That ridge interfered with how the back end of the case fit the chamber. So a couple of folks cut the middle section out of a standard full length sizing die, squared off its bottom then used it to size fired belted case bodies all the way up to the belt after using a standard full length sizing die with its neck lapped out to about 2 thousandths inch smaller than a loaded round's neck diameter. In other words, they returned the fired case back to virtual new case dimensions except for the shoulder which was set back only a couple thousandths so the belted case would actually headspace on the shoulder. Virtually all the matches won and records set were from fired cases so sized.
Some of the US military rifle teams tried reloading their 30 caliber magnum fired cases with traditional full length dies alone and got poor results. So they just used brand new cases winning all sorts of matches and setting records with them.
Innovative Technologies now has a collet die to size the ridge down on sized fired cases. Innovative Technologies - Reloading Equipment
has info on it. And either Redding or RCBS make excellent full length bushing dies for reloading belted cases along with the Larry Willis collet one.