They are probably close to calculated value, the thing is the 20mm and .50cal hits at 500-800 yards out, I regulary kill at 800 yards with 20mms, and only the A20 and to some extent F4us seem to be doing the same thing at that distance at me.
The real life 50-300 yards shooting range, where 2 .50cal = 20mm is as it should be.
I think a new damage model would help the .50 caliber, so would a icon with no range (only +1k and -1k on it help, not only at closing in, but also aginst the HO's.
Get rid of the range alltogether for the wirbies, they have the advantage of ambush and kill you before the icon show up at your own field.
50s have always been nerfed. Part is the lack of hitting power but the damage model is more to blame. HT thinks 20s are howitzers and 50s are paint pellets. Jug should have about the same snap shot ability as a Spit16. Not even close in game. Either 20s are overmodeled or .50s are undermodeled. Since I've fired the ma deuce and seen the results... I'll say the .50 is not just undermodeled, they're an insult to a legendary weapon which is still in use today.