I cant get my rounds to chamber once they are loaded what should be the overall length of the round (.270-08) using .308 lapua brass and a berger 150 gr. bullet once it is loaded. Also my dies wont neck the round down close enough to the shoulder without putting a donut on the top of the shoulder on the brass , what would be causing this? I am using RCBS 270-308 dies that came with the gun I purchased this is my first go round with a wildcat round and handloading for that matter can anyone help me out I cant find the chamber measuring tool I need for this gun to determine how long the overall length should be once loaded so any general info for overall length on this round with a 150 gr. bullet would be greatly appreciated, along with load data using lapua brass,berger 150 gr. bullet,winchester primer, and IMR 4064 powder Im not sure of the twist rate on the barrel is there any way to tell what it is. there is alot more I need to know but I have been messing with it for so long today Im just tired of it and cant think of everything right now.