Rate of Fire displayed in the game is ambiguous/inaacurate

For instance, the game specifies a RoF of "1200" for the AC42 assault rifle, which might make you believe that it's the fastest firing gun in the game - far from it actually!

I've just done some testing on a custom portal game that indicates the number of rounds fired (experience code: AAQ25J). On BURST fire mode, I can shoot approximately 480 bullets/min with the AC42, which is equivalent to 160 bursts of 3 rounds (and therefore 160x trigger hits on a controller). The rate at which I'm hitting the trigger on my controller is not a limiting factor when using the AC42 because I managed to fire roughly 300 bursts!!! with the K30 within 1 min (600 bullets). The game displays a RoF of "1100" for the K30 and yet its burst RoF is considerably higher than that of the AC42 (620 vs 480 rounds/min). To make matters worse, the K30 fires about 1150 bullets/min on full auto mode, which is nearly 3 times greater than the AC42 firing rate!!! I've also tested other assault rifles (AK24 [~650 rpm] and M5A3 [~800 rpm]), both of which fired many more rounds than the AC42 on full auto mode. Ironically, the AC42 might be one of the slowest firing guns in the game!

So what could explain the RoF specified? Different unit used to indicate burst vs full auto RoF? Numbers displayed in game are incorrect? Max (actual) rate of fire should be higher than actual? Arbitrary numbers??? I'm not demanding tweaks to weapon stats here, just want the stats displayed in game to be more meaningful!