I also want to make custom weapons and need to know of a suitable program.

Blender, 3ds Max, Autodesk Maya, etc. There are many suitable programs. I personally use 3ds Max but Blender may have an easier learning curve. It all depends on how familiar you are with 3d modeling in the first place.

Thanks! I've been using ArchiCAD, an architectural modeling program that can draw in 2D and 3D simultaneaously,for a few years but its too specialized.

I once used Blender for a shield, I only could make it with tutorial cause it was pretty hard for me as I am amateur at modelling. But I made the shield. I only had problem adding some colour/texture for that shield. Later I tried to make a church by tutorial, but I ended right there cause I still could not add any textures from the outside of program.