Offtopic: Hmm, I was gonna post about the something similar, but it would only be useable with the Default Gun.
Ontopic: This could be used as a /cmd like, /holster or whatever,and would only be usable if you had a default gun in your inventory. Or, it could be an item/weapon that always has a gun in it and always appears "on" you even when you put it (the gun) away, since it's a holster. That would be cool. =)