You have an SBR with a can? Ha, kickass. I've just got a piston 16". Anyway, for the gas block, I would just add more edges to round out the shape, and add an additonal loop so those two poles closest to the front aren't being "pulled".
You don't have to keep all the loops clean. You can remove some edges and leave some ngons on flat areas, where smooth edges won't be affected. You only use it for highpoly baking right? It won't cause any troubles on the normal map or so, if you do it right.