With a single gun, you first pick a firing mode: SA/BF/FA. It's a Minor to switch weapon mode.
- Under SA, under RAW you can only attack 1 person: You fire 2 rounds at the same person, which is -2AR/+1DV. No two-target option mentioned.
- Under BF, you can either do 1x -4AR/+2DV attack against 1 person, or use Multiple Attacks and split dicepool for 2x -2AR/+1DV attacks against 2 people.
- Under FA, you can do attacks that all are at -6 AR, and can do as many attacks as you want (with the implied but not mentioned limit of 10 due to only 10 rounds), split over as many targets as you want (and one target can take multiple attacks), this does NOT require Multiple Attacks, but you split your dicepool over the attacks combined. GM will have to decide whether it's possible to hit all your targets in 1 burst.