The DPS calcs in game are craptastic to begin with... average players showing 200k+ dps don't have it, at all. Say your smg shows 200k, in effect, you have to land each bullet from your clip as a headshot from lower than optimal range (which is basically kissing distance, as damage drops off in a matter of a foot or two). Stacking accuracy will "fool" the dps calc as well, as the game uses the stat to determine your headshot % (75 acc to the game means 75% of your shots land on heads).
You'll do far better just pushing each wep into the stats it wants to have...headshot on snipers, crits on smgs, etc, and not worrying about the numbers the game shows, as well as working out a "per mag" damage score instead of per second. My smg pushes 255k dps (as a mean score, averaging between blind fire body/head combos and stunned enemy headshot rampages) in actual use, but by the games calculations, it only has 176k. It pushes it's entire mag in 3.2 seconds (750 rpm with a mag of 40), so again, by the games calculations, it should drop 563200 damage per mag, assuming an average of 20k per shot (low, but it's nice and round and shows the difference quite well, stick with me) ....however, when each lands as a headshot, each mag drops an average of 800k in damage, peaking well over 1 mil with a good crit string.
....it's also only a backup for tight spots, as my AR can do equal damage, but from a block away instead of right next to an enemy, and my sniper can push 200k per shot nearly or at the games maximum distance to land a hit.
Bonus: Do most of your shots land as headshots already? The One is None talent can extended your mag by 35-60%, increasing your dps/per mag dramatically, but the game won't factor it in either for it's own dps calculations.
