As of now there isn't any clear evidence either way.

Personally I hope that they just set weapon damage just to match the style of play intended for the gun in question. I'd still issue the caveat that BO wasn't especially good at this. Only recently did they patch it so that sniper rifles could land lethal headshots even when silenced. Bearing that in mind I can't help but think that they haven't devoted a lot of thought into how powerful any given weapon should be.

eh I really doubt the damage is THAT much stronger. guns in both BO and MW2 did the same dmg range. ARs on average were 40-30 (weaker was30-20) SMGs were 30-20 (some were 40-20) and that's how it was in both games. SP didn't really do THAT much of a difference. bumping up dmg by 40% means guns killed faster by one bullet. Recoil is what made the difference.

rather I wish they lowered damage or made the damage range wider. 40 close for ARs 25 far. SMGs 30 close mid 20 far 15 and so forth.

...seriously