I'm doing load development for my new .223 Vanguard (VA38223RR4T) Accuguard w/ #3 barrel. I'm not getting good results and need help diagnosing the problem(s). These are 5 shot groups at 100 yards, fired round-robin with 5 minutes between strings. The rifle was on front and rear bags, shooting prone. It's in the factory tupperware stock which I think is part of the issue, and I did pillar bed the stock and free-float the barrel before shooting these groups. I made sure all scope, base, and action screws were correctly torqued to their factory specs. Group 3 is technically sub-moa, but why the vertical stringing? The sighter/fouler group at upper left is my standard 55gr AR-15 load of 23gr N133 with the same brass and primer.