ARX is c400 steel and either inconel or that cobalt wonder metal leading edges on the bore aperture. The ARX and VOX are not quiet by any stretch but are light and retarded strong. Find another 30 cal can with no barrel length restriction on a 300 rum. Dont know who thinks a 5 inch 300 rum is a good idea but EA has ya covered. If you want to dump your ARX let me know.It was the ARX, their titanium 5.56 can. Initial results were very poor. It's starting to quiet down some but I find myself shooting sub guns now.