Here is the interior design of Montana's guns as well as information on it because one of you asked about it.
His gun barrels will split so they can be used as electro-magnetic rail guns and when the barrels are together they fire regular shells.
He can fire 48 shots a minute so 4 shots per barrel
But when he gets his two skill activations combined he has a less than 5 second reload and can fire over and over again repeatedly
He either fires a steel rod or regular shells with gun powder
His ammo is stored in the turret and is brought up with a tall claw like clamp that grabs the ammo then brings it up and slides it into the Barrell
When the ammo is almost completely used up more is automatically brought up from the storage room below the turret.
Montana's ship always carries a months worth of ammo so over 20,000 rounds he has 10,000 of each kind.