final results from one of my AR builds
rock river 16" m4 barrel , 1-8 twist
troy ind. mrf 10? with cut for fixed a-2 sight
lauer weaponry lower , dpms m4 upper with m4 cuts
AAC spr/m4 blackout hider for my suppressor (see the PAI build in hide rifles forum)
ti-ni bolt carrier ass'y
magpul UBR
leupold mk m2 w/ 77 grain bdc , TMR reticle
runs and drives like a dream