Do you guys have any idea what the proper spec is on the 118LR loads for the M40A1 is on neck tension? I assume these rounds had alot of grip, but was wondering what bushing size is used in the dies. Thanks alot.
That is something you will have to measure yourself. I have a Palma rifle that has the 95 Palma chamber is is tighter than my M118LR chambered sniper stick. You can just measure a loaded cartridge on the neck and subtract .002 to .003 to get the dimensions you need. I use Forrester dies they can make you a custom die or get the bushing bump die.
I chrono the M118LR that i shot with my M40A3 then i worked up a load that would match the same MV that my gun shoots with M118LR and my data is pretty much the same with either M118LR or my reloads. I took my time to worked up that load as safely as i could but i do full lenght resize instead of neck. Hope that helps a little.