Technically, the amount of bullets that the guns can carry varies from the game they come from.
Cerberus should have a max of 51 though, that gives you ... 17 different shots.
Death Penalty ... I admit, I never finished DoC ... so, each round/bullet must be loaded individually ... but it's a hecka powerful weapon either way.
(Ignore my DP suggestion, but follow the Cerberus one ...)