My gas gun load development

[Burt Gummer]

Are you annealing your brass, and checking neck size for bullet tension?

Those two things will effect your accuracy in a huge way. Plus you need to remember you are shooting a gas gun, but you do have a pretty good barrel.

What's the rate of twist on it, and how many rounds down the tube?

I anneal every other firing using 750 degree tempilaq as a guide. A Mighty Armory FL die for sizing with provided expander mandrel. I don’t check neck tension since I don’t have the tools to do anything about it. 

The inconsistencies I was referring to in the above post when bumping the shoulder, I get swings by as much as .003”. This causes me to have to run cases through three or four times and shrinking the shoulder slightly more each time so that they are all within .0005-.0001”. I know this isn’t normal and the research I have done indicates I’m not using enough lube on the cases (Dillon lube) and it’s causing too much friction thus throwing the sizes off. I haven’t had any fired brass to try this out on yet. Any thoughts?