Even though I uploaded my M3A1 Greasegun roughly one year ago, I thought it would still be interesting for some people to see my textures and wireframe, so here you go.
I tried to actually model as many details as possible as floaters. So are all the letters, marks, weldings and even the knurling fully modeled and then baked down on the normal map. The vertex count for the high poly was roughly 2.5 million. The stripe to hold the jungle magazine was also made in 3DS. I only extruded a couple of edges around the magazine, added a shell, turbosmooth and noise modifier.
Some areas of the lowpoly may seem unoptimized, but I left the vertices there on purpose as Arma is quite funky when it comes to face shading. It bumped up the final vertex count a bit, but helped achieving the wanted look in the engine.
Tweaking the textures is a very difficult task as the shader in ArmA3s VR Engine has some quirks.
See the project in its final form here:
https://www.artstation.com/artwork/ZdvER