I can compile the model I'm working with no problem, and it's in the game no problem: the textures show up and when an NPC is holding it, it looks fine (minor clipping, but whatever). However, when an NPC drops it, it goes all weird. There's obviously something wrong with the physics model, but I can't seem to figure it out.

I save the model as the reference SMD, and then save it again as phymodel.smd

I compile the model, and it goes without a hitch. Here's my .qc

Like I said the gun is held by NPCs no problem. It fires and there's a muzzleflash, it's textured, everything works fine aside from the physics model (as in, when the gun is on the ground).

I approach the gun in Lost Coast (see its shadow?)

I grab the gun with the gravity gun. Notice that the gun itself is off to the lower left side, and it's vertical.

After grabbing it, I put it back down and it lands like this.

This is the model in the SDK model viewer, with "Physics Model" checked under the "Render" tab. It looks fine, right? I have no idea why it's behaving the way it is in game.

Is there some kind of command I can put in the .qc file to fix this, or is it a compiling error? I really couldn't say, I'm very new at all this so I don't really know what to do. Any help would be very appreciated :)