When the ship is rotating, the DK10 Arbalest very frequently fires 4 or even 5 shells in a row instead of 3 on the description. And very probably other 'repeating' weapons go like this too.
Also, I'm currently doing further playtest with my mod, and found that 'repeating' weapons with no ammo/charge left (when fired the last one ammo/charge) fire but just one and none of the rest of 'repeating' shells/beams.
I'd say this one is a rather frequent glitch in many action games...