Varget seems to be "hit or miss" with some rifles. I couldn't get it to work and moved to IMR4064 which gave me an immediate shrinkage in group size (from around 1.5 to 2 MOA down to .75 to 1 MOA).
That was using CCI-BR2 primers and Winchester brass with a 168 SMK. I've been very impressed with the Wolf SRM primers I use in 223 that I'm thinking of ordering a sleeve of LR primers next time I make a mass purchase (if they are available).
Machine guns are awesome until you have to carry one.