Hi, I'm on here representing my group. We've run into a problem, and I hope we are calculating incorrectly. Please look over the following, and let me know if you see any errors.
The tactical marine in our group used hellfire rounds in a storm bolter. A storm bolter fires two bullets at a time (up to 8). Due to the tearing quality, three d10s are rolled for each bullet (one discarded), for a total of six dice being rolled per shot (two discarded). Since righteous fury may be scored on a roll of nine or ten (hellfire rounds) you end up with about a 74% chance of righteous fury triggering per bullet. This is likely to stack multiple times.
Now, when Full-Auto fire is used, based on the description in the book, if any of the dice from the attack are 9 or 10, the entire attack is repeated (up to eight shots again). I have to assume that this is an error, and that each bullet triggers separately, adding the extra damage from ONE bullet for each Righteous Fury triggered.
So, even the weaker of our two interpretations leads to massive damage rolls--the equivalent of 20-30 bullets, except much more powerful, since each of these are clusters of 3-4 damage rolls that all stack together before armor and toughness are deducted.
So this is our interpretation, as per our reading of the text. I sincerely hope someone can cite a rule that we are missing, or have miss-read.
Thank you for your time.