2 Heritage Arms Victory Turbine muzzle breaks. The best you can get short of a suppressor! Green is for 416 Barret (and smaller) the grey is 458 Vestal (and smaller) they are 1-14 threads. $250ea

AI (Accuracy Internationsl) triple port 50 BMG M24x1 threads muzzle break. $450 (cheaper than Eurooptics). 

Sig muzzle break (30 cal)

Fat Bastard 338LM muzzle break 3/4x24 threads Gen 2. Taken off AI AXSR. $100

Taran Tactical 2011 baseplate black, 7mm ($25)

Misc 1911 parts