Copy model + armature to other file? I have a problem. I've made a model (a gatling gun), and now I need to add another model (a cowboy) to the scene, but the second model is rigged and has animations, and I can't copy both the mesh and armature! Whenever I try, only the mesh copies, and I can't see any bones at all.

I've looked around, and I can't seem to find any solution to this that actually works. I can work around it by copying the gun into the cowboys scene since the gun isn't rigged, but the thing is that I'll be making a rigged horse model soon, and then I'll need to have the cowboy and horse in the same scene. So I need a proper solution to this problem anyway.

Hope you guys can help me. Thanks a lot!
Your problem probably stems from trying to copy the armature in pose mode. Switch it to object mode and select both - armature and mesh. Copy it and paste to another file.
Second way is to append the cowboy from its file to the file on which you working by going to File>Append (or SHIFT+F1)finding the file, opening it, then folder Objects and choosing cowboy object. It will bring the cowboy object along with it's parent (in this example armature).