Man-Portable Mini-Guns?

[Anthony]

Originally Posted by Pursuivant

The one emerging role where I could see a man-portable minigun being used is as a drone defense.

Rather than miniguns, they seem to be dragging flak guns that would look familiar in WWII out of storage.

[Rupert]

[QUOTE=Pursuivant;2499170]

Originally Posted by mlangsdorf

The two traditional problems with man-portable miniguns are ammunition weight and recoil force.

Which makes me wonder whether the weapon harness described in Ultra-Tech might have real world applications, if only as a prop.

The only way a man-portable mini-gun in military caliber would be useful is if you reduced the rate of fire to near normal infantry MG rates of fire and reduced the number of barrels to 3 or 4. Since machine gunners carry spare barrels, no reason not to mount them on the gun to begin with. Rotating barrels might help keep them cool, which would aid useful lifespan.

That means the whole gun weighs more, and there's more mechanical complexity. You could use a Russian-style gas operated rotation system, rather then the US-style one with motor, and thus save on the battery weight, but the revolving mechanism will still be heavy. Also, putting the pare barrels on the gun adds weight - normally the loader/gunner's assistant carries them, thus spreading the weight between 2+ people, rather than making the poor gunner carry it all.

The one emerging role where I could see a man-portable minigun being used is as a drone defense. It's not economical to shoot MANPADS missiles at the sort of small suicide, attack and recon drones being used in Syria and Ukraine and conventional infantry MGs might struggle in the AA role. The gun could switch computer-aided chaingun AA mode for squad anti-drone defense to single-barrel operation when engaging ground targets.

As this isn't a man-portable role once you add in the required fire-control, you're really deciding between a mini-gun for rate of fire vs an HMG for reach, and modern Russian/ex-Soviet HMGs don't have the low RoF of the (ground versions of) .50 BMG. The minigun might make sense for a light anti-drone weapon for the US military. For much of the rest of the world a KPV or a couple of DShK's with whatever the fire-control system is mounted with them would be a better choice (readily available guns and ammo, good reach and punch). Using HMGs has the added advantage of making the system useful for shooting up lightly armoured (i.e. small arms-proof) vehicles.

Originally Posted by Anthony

Rather than miniguns, they seem to be dragging flak guns that would look familiar in WWII out of storage.

Towed KPVs never really went away, they were just stashed if they weren't handed out to third-world allies for cheap airfield and AAM site defence. Those things are really only HMGs rather than 'cannons' because of an arbitrary calibre cut-off (greater than 15 mm to be an autocannon rather than a machinegun).

[Anthony]

Originally Posted by Rupert

Towed KPVs never really went away, they were just stashed if they weren't handed out to third-world allies for cheap airfield and AAM site defence. Those things are really only HMGs rather than 'cannons' because of an arbitrary calibre cut-off (greater than 15 mm to be an autocannon rather than a machinegun).

Oh, the systems I was thinking about are cannons. While I assume some drones get shot out of the air with rifles (for that matter, a shotgun is probably not a bad choice for low end drones), you really need radar to be particularly effective at it, at which point man-portable is a lost cause anyway.

[Varyon]

Originally Posted by Pursuivant

The only way a man-portable mini-gun in military caliber would be useful is if you reduced the rate of fire to near normal infantry MG rates of fire and reduced the number of barrels to 3 or 4. Since machine gunners carry spare barrels, no reason not to mount them on the gun to begin with. Rotating barrels might help keep them cool, which would aid useful lifespan.

I think weapon overheating is generally only an issue for mounted/emplaced machine guns, someone shoulder-firing a weapon typically isn't going to have to deal with that issue. And, with the fact that there aren't such weapons already in use (or even in testing as far as I'm aware), I'd say the decision has been made that the complexity, weight, bulk, etc of such a design isn't worth the ability to continuously fire without needing to pause to swap out the barrels.

Originally Posted by Anthony

Rather than miniguns, they seem to be dragging flak guns that would look familiar in WWII out of storage.

I mean, there are also Mosin rifles and Maxim guns (with modern optics, even) in use over there, so bringing out WWII flak guns isn't that surprising.

[johndallman]

Originally Posted by Varyon

I think weapon overheating is generally only an issue for mounted/emplaced machine guns, someone shoulder-firing a weapon typically isn't going to have to deal with that issue.

Well, shoulder-firing MGs is fairly pointless, because you can't keep them on target. Bipod-mounted LMGs or automatic rifles can quite easily be overheated by firing them too much, which is why soldiers are trained to fire short bursts.

[RyanW]

Originally Posted by Pursuivant

The gun could switch computer-aided chaingun AA mode for squad anti-drone defense to single-barrel operation when engaging ground targets.

I don't think that would be practical or necessary. You can just configure a rotary cannon to run at whatever speed you want, either as a fixed rate of fire or multiple options available at the flip of a switch.

[Polydamas]

Originally Posted by Rupert

Towed KPVs never really went away, they were just stashed if they weren't handed out to third-world allies for cheap airfield and AAM site defence. Those things are really only HMGs rather than 'cannons' because of an arbitrary calibre cut-off (greater than 15 mm to be an autocannon rather than a machinegun).

Humans divide continua into discontinuities, but I thought that the reason cannons start at 20 mm was that at around that calibre, its worth putting a bursting charge in the round, and that gives a weapon capabilities which a MG does not have?

At least that was the old German army thinking wasn't it?

[johndallman]

Originally Posted by Polydamas

I thought that the reason cannons start at 20 mm was that at around that calibre, its worth putting a bursting charge in the round, and that gives a weapon capabilities which a MG does not have?

That was the case for a long time, which was how the convention got established. The difficult bit was the fusing: you want an impact fuse that leaves room for explosive, and you'd really prefer anything you're firing at aircraft to burst if you miss before it lands. Having fused explosive shells landing in friendly territory causes lots of damage and complaints.

Nowadays this is possible in .50 calibre, and going smaller is fairly pointless: there isn't enough explosive to do significant damage to worthwhile targets.

[Polydamas]

Originally Posted by johndallman

That was the case for a long time, which was how the convention got established. The difficult bit was the fusing: you want an impact fuse that leaves room for explosive, and you'd really prefer anything you're firing at aircraft to burst if you miss before it lands. Having fused explosive shells landing in friendly territory causes lots of damage and complaints.

Nowadays this is possible in .50 calibre, and going smaller is fairly pointless: there isn't enough explosive to do significant damage to worthwhile targets.

I don't think it was just the fusing but also how much volume there was left for explosives after giving the shell thick-enough walls that it would not come apart in flight. One advantage of making dedicated bomb-chuckers low velocity is that it lets more of the round be explosive. But metallurgy (and the design of shell casings to make effective fragments) advances too.

[Anthony]

The other problem is that explosive rounds have low sectional density relative to their caliber, which means small explosive rounds have quite short range.