These are personal weapons, the PML and it's quad variant are envisioned in my game to be surprisingly similar to a bazooka kind of thing.
And the 50 people thing - we got a bit lazy, and rather than waste away playing time rolling 50 critical results, we agreed before the roll that one crit would affect all. And then She went and rolled a 92, so even though it was just an A, it was a plasma grenade so doing Impact, Heat and Radiation criticals off that result. Farewell to the grunts.
Unfortunately, this evening she tried that stunt again, and rolled very poorly, scoring a result of just 02 after the skill mod was added (the character has a negative skill). Unfortunately, the other side had a telepath who bounced the missile right back with interest using a Deflection psion. And the missile almost killed her - I did say that she needed to improve her AT.... If she had rolled much higher that triple C critical would have been an E or higher and it would have been a definite farewell.
The PCs have learned to rush in with stunners. Or better, throw in stun grenades and then wade in with machine guns loaded with HEAPDUCIC rounds. Even so I did manage to almost kill one PC (was looking up soul departure & stat deterioration rules), and blew the hand off another one. Time to relieve the PCs of some cash to replace that hand
And radius - I think it's 1m x mark per blast radius for point defence, standard are 2x, and enhanced are 3x - so a mk 5 enhanced has a ground zero effect of 15m radius, 2nd blast radius out to 30m... 75m total radius of effect. Big boom.