I have the following problem, I've modeled a rifle with a grenade laucher in 3dsMax and I've rigged it with bones so that it can be used in the first person view in my game. But there's a problem with the rifle, I need to setup a bone for the piece of the grenade laucher that slides for reloading, but I have no ideia how to do configure the bone hierarchy so that the bone slides instead of rotating around the parent. How do I do this?

Why not just make a dummy that's linked to the bone, and then link the moving piece to the dummy? Think that should solve it.