Actually I put the lower together a year or two back with surplus grip & stock thinking I'd go with a rifle configuration; I never thought I'd use a 16" bull barrel. But I got a very good deal on the barrel recently, and it is time I finished this project. The Sun Devil upper & lower set have been sitting around the house waiting on me for the last 4 years.
I guess I thought the M4 2-piece front end would look best with the A2 buttstock, and I've been having a hard time imagining which free-float tube would work best with which gas block. Some gas blocks seem to go within the forend, some right in front. Some free-float tubes have a screw-in front piece which would line up... where?
I guess I'm just coming to terms with the results of a snap decision.