All mine are home built. I have a 7.5" .223 pistol, 26" .936 White Oak Armament .223, 16" CMMG pistol gas .300 Blackout and a custom 17" .936 .22lr upper. All have Spikes Tactical lowers, DPMS parts kits and Magpul MIAD grips. The uppers on the pistol and Blackout are M4 flat tops and the 26"...