I think I understand the regular rifle damage, but completely lost trying to use Potted Plant's posts on the twin bolter. How do I calculate damage?
I have one magnitude including MIU and squad bonus, and do we add +3 magnitude for the swarm size? so +1 twin linked for 5? I didn't aim since I moved.
You get +20 to hit from twin-linked quality, +40 from horde size, and -10 because the gun only fires on full auto. So a net total of +50 to hit, I think.
Then you cause one hit for succeeding on the BS roll and one extra hit for each degree of success, up to the total of 6 hits. If you succeeded by two or more degrees, twin-linked quality gives +1 hit, and you get another +1 for explosive damage.
So yeah, it is a bit complicated with all the modifiers.
41 Base +20 Twin -20 Running -10 Full Auto +40 Size +6 Squad Bonus from Tiberius (unless you are specifically wanting to stay in Solo Mode) = 71, or 77 if you are in Squad Mode. With a roll of a 44, that's 1 Success plus 2 DoS (or 3 DoS if you're in Squad Mode).
That would be 1 Hit + 2 (or 3) for DoS + 1 for Twin + 1 for Explosive (Bolt rounds are X damage type). That's either 5 or 6 Magnitude damage, depending. Did that make sense?