What about the swarmfire? I've never understood the integrations for it, it's always seemed like a subpar blaster, even overvolted.
I would hardly call better than stock Elite velocities and ROF up to 600RPM "subpar".
It's certainly an objectively superior system to a RF20 or MS, which are its closest common competitors in its most suited role.
Herbert West, the effective range is roughly that of a typical primary. Range IMO is no longer a consideration for the majority of our equipment, since aside from certain situations (micros at high velocity, as in blowguns, etc.) you are looking at effective range limited by projectile stability. A Swarmfire is not the best choice to get velocity from, but being high-rate full auto, that is not that huge a deal. And, it's a SMG anyway, you typically use it for close quarters.
The big deal about the integrations? You can add, in an unobtrusive package the size of a typical pistol:
A relatively high capacity secondary weapon (superior to most alternatives except those that are mag-fed).
A source of suppressive fire when needed.
An underslung system that is much more useful as a backup weapon than the norm.
A more versatile and efficient approach to suppression/area fire/foam spam than shotguns.
How about the alternatives? Roughcut (4 shots, 8 separate projectiles, pump action), various pistols (6-10 shots), poppers (2 or 3 shots max with 7 projectiles per shot, terrible velocity/range) or absolved pneumatics (2 shots max, typ. 7 projectiles per shot, up to 19 but only practical with a single-shot device). Not too good, the swarmfire gets you at least 8 potential bursts with 20 projectiles available for spamming and is usually smaller and lighter with superior follow-up shot and defensive utility.
BTW, Swarmfire cylinders are droppable from the factory. That always seems to be forgotten, and I never make use of it but it's possible. Key ring on the retainer and a few extras and you have yourself a much faster swarm reload.