Incredibly well. The long rifle length gas system is a smooth recoil impulse and is designed to work with mil-spec lowers / mil-spec components. The Romeo barrel from Dynamic Defense Inc. is 16 inches long, features .223 wylde chamber with a 1:8 twist, and sports a Melonite finish. The 1:8 twist is a particular favorite of mine as it suits the typical weight of rounds I’m sending down-range. Speaking of down-range, this thing is very accurate. Firing at a target at 100m utilizing a Steiner Mx5i 1-5x optic I averaged 1.9 MOA groups with reloaded ammunition. I’ve no doubt this rifle could do better with a better shooter, trigger and optic. Dynamic Defense states the barrel can do 1 MOA or better and I have no reason to doubt them based on my experiences. The Melonite finish is a favorite of mine as well, as I’ve experienced excellent wear resistance and performance from these finishes.
The recoil is near negligible. Follow up shots are as fast as what I do with my MK18 but the difference is that I don’t have to try nearly as hard. Because the recoil impulse is smooth and more gentle I fight the gun a lot less through its recoil cycle compared to carbines with shorter gas systems / barrels. With more time behind the gun I’ve no doubt that my split times will continue to fall. The recoil impulse feels somewhere between a 20 inch M16A4 and a 16 inch mid-length which given the hybridization between the two makes sense. Nothing feels quite as soft as a 20 inch barrel with a rifle length recoil spring. However, Pairing the Romeo upper with a lower outfitted with the Vltor A5 system (essentially a rifle length gas spring) made for a game winning combo. Pulling the trigger and sending rounds on target is almost like firing a 22LR.