Lightweight 16" AR, 5.56 chamber, NiB coated BCG, simple flash hider, simple RDS or laser and BUIS, maybe 6 pounds or so.

Medium 18", .223 Wylde Chamber, 1-4 or 1-5 optic in one piece mount, carbon fiber HG, low mass BCG, comp.

Heavy 20", .223 Wylde Chamber, 3 or 4 x on bottom to 12 to 20x on top, threaded for suppressor, Seekins flat bottom HG, standard carrier with enhanced bolt.