Scythe gun

Having lots of guns, or at least a gun with lots of barrels seems like it must weigh one down unnecessarily.
Presumably what the shooter wants in these cases is a wide horizontal spread of high-velocity particles for scything down a wave of enemies at short range.
Effectively a manually aimed and triggered claymore mine.

I suggest that this could be achieved by simultaneously firing two relatively large particles at an angle, but joined together by a relatively lightweight wire or chain.
In designing such a beast, one then encounters the difficulty of how to project this suite. Gun barrels are long and thin, with the projectile forming a seal so it can be efficiently accelerated by gas pressure. A triangular barrel is unlikely to function well.
Suppose that one had a V-shaped tube, with each side representing one barrel. A specially designed cartridge could simultaneously fire a bullet down each barrel. I propose using a similar method to the rifle-fired grenade. In modern use these sit over the end of the barrel; the bullet embeds itself into the rear end of this with the combined mass proceeding to the target. So I propose that the same could be done here, with the terminal caps of the chain sitting over each barrel.

To reduce drag, much of the chain may be packed into a sabot, to unreel during flight. This could potentially be projected in-between the end-caps to promote a more linear form in flight.

Re-loading might be a little slow.