Not exactly a weapon "modeler", so can't say much but this question: Is answered to me by this top of the post: Subd is a part of modeling since you wanted to go back to modeling I'd say you are doing what you wanted by going back to the roots.
Had some free time this weekend. The front view of the concept is my main reference, and I liked the shape of the backside from that view. However, trying to cajole the model to match that reference was a major pain in my backside. Ultimatly I decided sticking to the front view for the back of the weapon would result in a…