If its a .50ae, it will be theoretically a XIX no matter what. If its a .44mag or a .357 the way to tell is in the barrel profile and the safeties. An XIX will have weight reducing flutes milled into the sides and sight slots on the top of the barrel. The safety will have a "hook" that extends down off of it. A VII will have a thin profile on the top of the barrel that will not accept a scope without a special mount that has to be purchased seperately and the safety lever is just a basic egg shape. Hope this helps out...