This is a perfect upper for a military clone build. Very high quality. FNH and Colt, as well as LMT and Knights Armament served as the backbone of tCharlie's Custom Cloneshe US military’s upper and lower receivers. Amongst those who know, FNH is well respected. In addition to building the upper and lower receivers for the M16 and M4 family, FNH also is the leading barrel manufacturer for the military and to other brands, using buttoned rifling for the M16, and CHF double chrome lining for the M240 machine gun. Many of the most popular commercial AR15 brands on the market, using cold hammer forged barrels get their barrels from FNH. This is where quality begins.