Three big differences:
One, they are +5 to Shooting Value. That's a lot, and it represents a stream of bullets. Lots of bullets makes it easier to get a hit (aka, "spray and pray"). If you shoot it at one unarmored individual, you are either going to have a critical failure (roll a 1) or hit him.
Two, you can spread that +5 value across any figures within 2" of each other. So, if there are three figures spaced 2" apart, you can allocate the shot as +1, +2, +2, or whatever. Less likely to hit, but you can hit all three.
Third, and this is where it gets really nasty, is that if the target is in a group (defined as in base-to-base contact), then you can put the whole +5 on each member of the group. So, if they have grouped up to fire a volley… mow 'em down with a machinegun.
This happened at one of my son's games against a friend. He put eight of his guys together to form a super volley. The enemy got a machinegun into line of sight. Hit every single one of them; five failed their Pluck rolls.
takes another stab at building a more perfect flight stand.
