Is it possible to have a model use another model's shadow volume, like with the option file or something? Basically, I want to take the shipped clone rifle's shadow and assign it to the JKA clone rifle. Is this possible?

Why? does it not have a Shadowvolume?

It may have to be re converted, and have a shadow added.
I don't know of any way to do what your asking.

No, it doesn't. I've been reluctant to include it in my mod, so I've reskinned the shipped rifle. Looks decent enough, but the JKA rifle is far better - but it lacks a shadow, which doesn't look too good.