Burst Fire Options
1. Short Burst - Fire 1d4+1 rounds (2-5; may be different for other weapons), or 3 if the weapon has a 3-round burst option. Your attribute comparison is for the entire burst and is not compared for each individual shot. You receive a bonus of +2 to hit with a short burst. This shot is also more deadly because the bonus will make it more likely that you will score the maximum gradient of success.
2. Medium Burst - Fire 1d4+3 rounds, for a +3 bonus but a penalty (-1) to the actual effect. Therefore, you are more likely to score a hit, but because it's harder to control larger bursts, the quality of your hit will be poorer.
3. Long Burst - Fire 1d4+5 rounds for a +4 bonus, but your hit quality is poorest, at -2.
Note: Therefore, in most situations, it is wisest to fire short bursts. This seems to be the case in real life. Even in modern video games, this dynamic is apparent. Take note that the rounds fired are the base number, and will change with weapons with differing rates of fire.
Spread (It's a pain in the ass digging up my scribbled notes on this one; it's lost in a sea of scrapped ideas. Bear with me here as the spread mechanics are not fully fleshed out yet.)
Anyway, the basic idea is that for every square you threaten, you suffer -1 to your attack. Short burst can threaten 2 squares total, 3 squares for medium and 4 squares for long.
I can imagine that at this point, the calculations will be a pain in the ass: Attribute + 1d4-1 + burst - spread (then roll for shots fired) - cover - distance...fuck! So, a 7 focus shooting at three targets (passive def 6) amongst 4 squares past 7 yards would be:
6 + 1d4-1 (8) + 4 (12) - 4 (8) - 1 (7) vs. 6 passive defense = 1 effect (1 is minimum for burst fire effect penalty) and 7 rounds fired...that doesn't seem right, does it? I'll probably have to apply the randomizer to each target rather than uniformly. I will only know after I draw out more examples, but so far, I feel it emulates the inherent chaos of firefights.