[khazm]

I'm building a rear handled gun out of one solid unlaminated piece of black walnut. i'm gonna use a riffe handle and trigger. i'm going to build it as an open track gun and its going to have a track made for spears 5/16" and less. 3 5/16" x 20" bands. Riffe trigger mechanism, handle, everything. 45" long. The only question i have is what should the other dimensions of the wood be? i don't have any of the parts yet and really want to get the wood cut. All help is appreciated greatly!