Bear Creek Arsenal Complete Uppers

[drykilned]

My 18" stainless hbar in anderson upper receiver, 12.5" round free floated handguard, with the anderson lower off my 5.56 shot 3 3shot sub moa groups after only 2 rounds before. (1) get on paper at 25 yds and(2) make sure sight corrections got there for 100 yds. 140 grain speer, 28 grains cfe 123. By the way, barrel is bca from american classic. Waiting for my second magazine. Already lost the first one after i tuned it to feed correctly. Using the 140's to break it in. Left over from 6.5x55. Disappointing velocities at 2110fps.

Is the 5r rifling supposed to drop velocity?