On 12/2/2019 at 6:56 PM, P-47 Thunderbolt said:
To fire, the character designates a number of targets up to remaining ammo and makes an Average Computers check (with the attack difficulty of the toughest opponent). If they hit, they can spend 1 Advantage to trigger a hit on a designated target.
This would mean that the Mandalorian would have needed a roll of 2s3a to take out all 4 Starmtroopers.
In game terms, he could have been facing a minion group and just rolled really well. A weapon with a high enough Pierce or Breach would mean he only needed to do 20 wounds. Or, given the blast quality, only needed to do 5ish wounds to each.