Hardened Arms 300 BLK upper with SMC muzzle brake. Very clean, only 210 rounds through it. 1:8 twist rate. No BCG or charging handle. It mated perfectly to my DDM4v7. Think I paid about $450 for it. Selling for $150. I’m in the Cherry Hill/Mt. Laurel area. Willing to meet if not too far or will ship for $20.
Carbine gas or pistol gas system
I measure 4.25” from front of receiver to back of gas block. Total length of gas tube is 5.9”.