And yet, again, it didn't have to be written that way. Maybe instead of Peacemaker, this could have been a more powerful weapon like Cerberus or Death Penalty. Or the Peacemaker could have the weapon whose power level is just below Death Penalty. You know what other location would have made sense to have a gun lying around..? JUNON! Of all the weapons you can purchase in Junon, they mysteriously offer up no handguns. And you can buy Peacemaker here... on Disc 2. But why?
Considering the criminal element, wouldn't make sense to find a gun at Corel Prison? Maybe one of the bandits' drops or stealable...

You know what would have been a neat unique skill for Vincent, to set him apart from Barret as "ranged guy", let him wield two guns.