37% - 0 dmg
36% - 1.25 dmg
22% - 2.5 dmg
5% - 3.75 dmg (taken from smurfy)
Weighted average - 1.1875 dmg per shot.
Of that, 15% is transferred to structure - 0.178125 dmg per shot.
Machine guns have a 0.1 recycle rate = 1.78125 crit DPS
Combined with the regular machine gun DPS of 1, an individual MG can do 2.78125 DPS to structure
4 MGs = 11.125 DPS to structure purely with machine guns. This is a 3 ton weapon system. (minimum)
Now, combine that with a swarm pack of unhittable Spider-5Ks, and you're taking out mechs RIDICULOUSLY quick. Thank god this doesn't work on armor.
Of course, you're not going to connect with every MG shot, but the averages work out.
EDIT: Don't get me wrong here. I think their damage against armour is fine, but their damage straight to structure could be tweaked down a bit.
Whether this be done via lowering the bonus crit damage, the bonus crit chance, the crit damage transfer ratio (though weapon-specific exceptions are tough to swallow) is up to PGI.
Much <3 (by the way, the MGs are hitscan)
EDIT2: edited the title to be a little less alarmist
Edited by rdmx, 11 August 2013 - 07:17 PM.