[Kromm]

Massed fire should only use the rapid-fire rules in two situations:

1. When the weapons are "synchronized" or "linked" to let a single gunner discharge them all at a single target as if he were firing a single, high-RoF weapon. Not all of the weapons are in the exact same spot, and a gunner who lacks traits like Compartmentalized Mind and Enhanced Tracking must aim using a single gunsight that won't be zeroed to all of them, so there will perforce be some dispersion.

2. When the weapons are individually fired, but are close enough together that the smoke, flash, recoil, power surge, etc. from one could become an issue for another. In that case, individual gunners work against one another somewhat. Peter's gun disturbs Paul's aim, since Peter and Paul aren't a hive mind and don't fire truly simultaneously.

However, if multiple gunners are aiming and firing weapons expressly set up not to interfere with each other, or if there's a fire-direction system that lets several weapons aim and fire truly simultaneously at a single target point with individual corrections – either option giving the effect of traits like Compartmentalized Mind and Enhanced Tracking – then I'd suggest separate attack rolls for the weapons. If two PCs standing nearby can fire their rifles as separate attacks, then two isolated gun crews, or a single computer that can run two instances of gunnery software to operate two guns, ought to make separate attack rolls for each weapon.