I wanted to do my own test of .223/5.56 55 grain ammo and since I had 5 different types/brands I thought it would be a cool little experiment. This test was done on a Stag Arms 2T 16" barrel, EO Tech XPS2 with Primary Arms 3x Magnifier. Wind was coming from the west (left) at about 5 mph. This was from 50 yards out. The Rifle was sighted in on Federal .223 which is interesting because it performed pretty bad in the test. I did 5 round groups as the sample size.
The Freedom Ammunitions .223 Reman ammo seemed to perform the best.
my 2 cents, or rather $12.50 @ .50 cents per round, hehe