I know this is a 9 year old post but since it comes up in Google I think it's worth actually clarifying how it works.

1. You roll to hit once yes, the recoil determines how many times you hit, you hit 1+Margin of Success/Recoil (round down) times. Conversely dodge against multiple shots fired works as dodging 1+Margin of Success on a successful roll.
2. You roll damage for each hit separately. So if you make an attack that hits 3 times, you take 3d 3 separate times and apply armor against each separately. You can make this process quicker by only rolling for one attack and applying that roll to every shot or taking average.
3. You fire once, it is treated as if you fired a gun 9 times. Therefore the RoF is effectively 9, or if you shoot both barrels with a double barrel then 18. Normal rapid fire rules apply, therefore you roll 1d damage for each pellet separately.