Jon Rush gave a workshop on "Modern Game art weapons". There were buttons clicked I didn't even know existed. As you can tell, it was a fun course. Highly recommend it!
This cool concept was by Diego Almazan and I added a little spin on it giving it more of a worn, used feel.
I used Maya to create the original hard surface, then into Zbrush for detailing and used XNormal to bake. Rendering was done in Marmoset 1.04. Not to mention good old Photoshop. Although there were tonnes of programs to jump from, somehow, it all felt streamlined with minimal 3D buggery.
The concept, high poly, extra shots and turnaround are available in a typical blog screen dump for you to err... enjoy.