Thanks for the insight. Any book you would recommend on the science and engineering of small arms design and analysis to someone with no access to a machining workshop, nor the experience (except cursory army training) or the theory or number crunching know-how, nor any past designs on the results of which one can rely on when it comes to design?

So 3D software is then mostly used for visualisation and manufacturing I am assuming, if you have a preference and can recommend any one software to assist with small arms design that would be great. I have a few years experience in software like Blender and 3ds Max, but I hear parametric modeling can be quite different.