Yeah, however, I've seen footage of a player picking up 76 rounds for Jolder's Hammer from one crate, as is supported by another comment. Using Field Scout, the last time I checked, I got 60 rounds and using Heavy Ammo+ without Field Scout it was 52 rounds. I'm guessing at this point that Surplus adds 25% to the ammo drop and it's Field Scout + Surplus, since that's what one of the players that got 70+ rounds was using.