Finished this up today. Semi-auto M4-style in .300 AAC Blackout. 10" Noveske barrel with pistol gas system. YHM smooth free-float quad rail. 2-stage trigger. Currently has a 4-position stock but will change that out to a VLTOR E-Mod this week when the VLTOR order shows up.
Also has a Yankee Hill Phantom suppressor on quick-detach flash-hider mount. Using 147gr supersonic ammo, sounds like an unsuppressed .22 pistol with Stingers. With 200gr subsonics, sounds like a pneumatic nail gun.