The "laser shotgun" design appears to be counterintuitive, as, unlike a ballistic weapon, there seems to be little point in splitting laser beams. However, this is hardly a new idea in science fiction - both Spacehounds of IPC by E.E. "Doc" Smith and The Puppet Masters by Robert Anson Heinlein feature "fan beam" mode for rayguns, which spreads several beams across a horizontal plane. It also appears that the energy required to messily tear a human target in two in a millisecond is comparable to the output of a conventional rifle.
Soldiers seem to try and chamber a new shell between shots, via racking the shotgun-style slide. This could be dispelling a used heat sink, most likely a small one as they never replace them - though this might be the reason for the "reload" requirement once the weapon has run out of "ammo".