Also still griping about the F44AA. Wrote a different thread about it. Damage should NOT be 2. An AK 4047 or 10mm Explosive Tip caseless M41A doing as much damage as a 5MM shot from an F44AA? No way.
I don't believe the game's damage values represent the different exact weapon's calibers, but an abstract capacity of inflicting damage... Be it by rate of fire, projectile velocity, or some other variables. For example, the F44AA, with its much larger magazine, may well be able to fire 5mm bullets at twice the rate of an M41A, but on the other hand, that makes it prone to jamming and malfunctions, and that's why it got replaced by the more trusty M41A.
On an anecdotal note, IIRC, the M41A was also prone to jamming when its magazine was totally full (99). That's why Colonial Marines usually removed some bullets from the magazines before inserting them.