The Patrol SL is our best value fighting rifle we offer. It houses a 4150CMV 1:7 twist 5.56mm barrel, Mil-spec buffer system, our Liberty Fighting Trigger, and B5 furniture. At Sons of Liberty Gun Works, we always tell our customers that it’s not what a rifle company tells you, it’s what they don’t tell you. Below you will find additional specifications of the M4-Patrol SL. We have built our guns to run through years of hard use, and we have nothing to hide.