RovingPedant said:

That's a lot of missiles for an IFV. Maybe provisions for fitting that many for specialist tasked vehicles while the majority don't carry so many?

In the current war - would you send one out without a full missile complement?

I would contend that miniguns were absolutely intended for vehicle use. You’d be hard pressed to find a minigun that isn’t mounted on a vehicle.

Perhaps not as a coax mount, but why shouldn’t you? Low rate of fire to conserve ammunition and suppressive fire, high rate for fleeting targets. You’ll probably suffer greater dispersion from 6 barrels vs one, but is that dispersion going to be a problem? Since you can get miniguns with a low rate of fire, because users had asked for that feature, suggests that there is a point to it. Also at low rates of fire you could hold the trigger down and expend several thousand rounds without overheating, while any single barrel MG is restricted to bursts and will suffer from heat-related increases in dispersion as the round counts increase.

RovingPedant said:

Perhaps not as a coax mount,

Miniguns are very rarely used in ground vehicles especially AFVs. If they are its usually because they have a very high rate of fire.
This is what I am refering to. The use of a minigun in a helicopter or any flying vehicle in general is not what I am talking about.

RovingPedant said:

but why shouldn’t you?

Because the gun is unnecessarily large. It also would need a very large opening to shoot trough.

RovingPedant said:

You’ll probably suffer greater dispersion from 6 barrels vs one

You definetly would. Which means you waste a lot of ammo.

RovingPedant said:

Since you can get miniguns with a low rate of fire, because users had asked for that feature,

Is that the case?
Which guns would that be? Who requested that, for which prupose?

RovingPedant said:

Also at low rates of fire you could hold the trigger down and expend several thousand rounds without overheating,

and why would this be necessary?

Its a fact that not a single military so far has ever seen the need to use a gun as coax that is significantly more capable than a common GPMG or MMG. At best a heavy barrel version is used or simply two guns are mounted. Even water cooled coax or AFV guns have been very rare and usually been dispensed with quickly even at the time when water cooled MMGs have been common.
No one used multi barrel guns in this role.
So cooling of coax MG doesn't seem to be that much of an issue. As well as burst length.

There simply is no tactical need for it. Just because something can be done doesn't mean it needs to be done or should be done.

schnuersi said:

You are aware that this weapon isn't actually used? It never made it past the prototype stage.

I wasn't - thanks!

Maybe, if fewer missiles meant more of something else. Also, you might not be able to give everyone a full loadout due to supply problems.

And hasn't it turned out regular old tube artillery has killed the most AFVs in Ukraine?

graylion said...

In the current war - would you send one out without a full missile complement?

I'd certainly try to make sure that there are enough missiles for every vehicle, but part of that is to limit the number of launchers on each vehicle. Launchers cost even when empty so I'd only fit the launchers I'd be confident of supplying. I'd also favour supplying more missiles to vehicles and sub-units that are focussed on their use, such as dedicated anti-air or anti-armour troops/platoons.

An infantry platoon vehicle might have a single launcher while the support company AA platoon carry two launchers stocked up with SAMs and an air search sensor and the ATGW platoon are running double launchers with ATGW and maybe a mast-mounted sight so they can engage from defilade.

schnuersi said...

Because the gun is unnecessarily large. It also would need a very large opening to shoot trough.

Given that a number of turret systems feature externally mounted coaxial guns that isn't necessarily so much of a problem.

schnuersi said...

You definetly would [get more dispersion with six barrels]. Which means you waste a lot of ammo.

Only if the increased dispersion is significant. Plus you would be comparing a hot single barrel with a much cooler six-barrel arrangement. Plus a modern FCS means you waste less ammo than an older FCS machine gun.

schnuersi said...

Is that the case? [that reduced fire rates on miniguns are available due to user requests]
Which guns would that be? Who requested that, for which prupose?

Profense's miniguns:

 https://rumble.com/vsrzeh-mini-gun-demo-by-profense-at-shot-show-industry-day-at-the-range.html

Requested by users who have them mounted on ground vehicles, for the purpose of reducing ammunition usage when it's not needed. I infer that's special forces.

schnuersi said...

and why would this be necessary?

Its a fact that not a single military so far has ever seen the need to use a gun as coax that is significantly more capable than a common GPMG or MMG. At best a heavy barrel version is used or simply two guns are mounted. Even water cooled coax or AFV guns have been very rare and usually been dispensed with quickly even at the time when water cooled MMGs have been common.
No one used multi barrel guns in this role.
So cooling of coax MG doesn't seem to be that much of an issue. As well as burst length.

There simply is no tactical need for it. Just because something can be done doesn't mean it needs to be done or should be done.

Conversely, just because no-one has done it so far doesn't mean that it shouldn't be done. No one fitted a camera system to an AFV until they did, as the performance of cameras and data transmission coupled with powered gun control improved. Now most AFVs carry more cameras than Hubble.

In terms of mounted machine guns, I recall that the Germans in WW2 favoured the MG34 over the MG42 because barrel change under armour was easier. The British Army operate a coaxial gun with a quick change (and heavy) barrel in the L94A1 chain gun. Water cooled AFV guns were typically dispensed with because the water jacket was vulnerable. See the comedy barrel shrouds on the Australian Sentinel prototype.

I've read that suppression effect is greater the more different characteristics are in play, so HE + MG fire has greater effect than either alone. Sticking in vastly different rates of fire might add to this.

schnuersi said...

Miniguns are very rarely used in ground vehicles especially AFVs. If they are its usually because they have a very high rate of fire.
This is what I am refering to. The use of a minigun in a helicopter or any flying vehicle in general is not what I am talking about.

I apologise. I knew that but my username was not chosen randomly.

It's only relatively recently that motor technology has permitted easy changes to fire rate without impacting reliability.

RovingPedant said:

Given that a number of turret systems feature externally mounted coaxial guns that isn't necessarily so much of a problem.

In this case the gun would not be protected by armor. Which for a fairly large and complex weapon doesn't seem like a good idea.

RovingPedant said:

Only if the increased dispersion is significant.

It is significant. I know the disperson of a M134D. Have seen it first hand. Its plain awefull. Conventional machine guns like the MG3 or MG4 have orders of magnitude less dispersion.

RovingPedant said:

Requested by users who have them mounted on ground vehicles, for the purpose of reducing ammunition usage when it's not needed. I infer that's special forces.

Ok so there is one case. This doesn't allow for the conclusion that this is allways a good solution for a general purpose gun. It could and most likely is a request that has been triggred by a specific situation and personal preference.

RovingPedant said:

Now most AFVs carry more cameras than Hubble.

Which is not true to start with. Some AFVs do. In most cases they carry one or two cameras. If it is a good idea to mount lots of cameras onto AFVs is still undecided. The reasons are also completly unrelated to the problem we are discussing so no conclusions can be drawn.

RovingPedant said:

I recall that the Germans in WW2 favoured the MG34 over the MG42 because barrel change under armour was easier.

No that is not correct. The barrel change of the MG42 is far easier and quicker. The coax MGs of German tanks of WW2 had to be fed from the right because the loaders position at this time has been on the right side of the turret. The MG34 can easily be mounted upside down for right side feeding. This is not possible to the same degree with the MG42.
Nowadays the loader is on the left and the MG3 mounted on the left side of the main gun. Even though the barrel changing port is on the right side facing the main gun its easiy and quick to change barrels.

RovingPedant said:

The British Army operate a coaxial gun with a quick change (and heavy) barrel in the L94A1 chain gun.

So apparently quick change and heavy barrel is sufficient.

RovingPedant said:

Sticking in vastly different rates of fire might add to this.

Pure speculation.
The experience of the German army suggests otherwise for example. Since there are few reliable examinations of supression its impossible to draw any conclusions.

schnuersi said...

Which is not true to start with. Some AFVs do. In most cases they carry one or two cameras. If it is a good idea to mount lots of cameras onto AFVs is still undecided. The reasons are also completly unrelated to the problem we are discussing so no conclusions can be drawn.

Most concept/new AFVs usually mount quite a few, while Hubble doesn't really mount that many. The point there is that while using lots of cameras may or may not be a good idea, it is the development of the technology that has made it more of a question than the previous situation where they clearly didn't have enough resolution/capability to be worth while. Things change and you have to revisit concepts with an open mind once in a while to find out if the reason is still valid

schnuersi said...

No that [MG34 barrel change in easier under armour] is not correct. The barrel change of the MG42 is far easier and quicker. The coax MGs of German tanks of WW2 had to be fed from the right because the loaders position at this time has been on the right side of the turret. The MG34 can easily be mounted upside down for right side feeding. This is not possible to the same degree with the MG42.

Isn't the barrel change procedure for the MG34 to pivot the receiver about a pivot parallel to bore axis and withdraw the barrel directly backwards, while the MG42 requires space alongside the barrel shroud since the barrel comes out sideways, pivoting somewhere about the muzzle device? Surely this means that the MG34 could be mounted further through an armour plate, particularly for bow gunner positions. My thinking here is that it is necessary to change the barrel on a single barrel gun.

schnuersi said...

So apparently quick change and heavy barrel is sufficient.

The key bit being the quick change, which adds certain complications onto the design and where you can mount the gun. If it's external or on a RWS then changing the barrel is not so easy. If you need to change the barrel, then overheating is an issue that needs to be addressed in one way or another. That RLS even prototyped the 3-barrel auto-change thing suggests that weapon overheating is a concern. Even if it can be managed, making the management easier is probably worth a look at.

schnuersi said...

Ok so there is one case. This doesn't allow for the conclusion that this is allways a good solution for a general purpose gun. It could and most likely is a request that has been triggred by a specific situation and personal preference.

One case that shows that one of the main objections for the use of miniguns no longer exists.

schnuersi said...

In this case the gun would not be protected by armor. Which for a fairly large and complex weapon doesn't seem like a good idea.

Few if any RWS feature protection for the gun, but if you wanted to protect the gun the firing barrel is only every in one place and you could protect all by the firing barrel if you could deal with the cooling and gas that would trap. Which you have to do with most GPMGs anyway. Accepting that a minigun on high rate will be generating quite a bit more gas, but at the same time there's a longer lock time so less gas is in the case when it's ejected.

I don't think that a minigun is definitely the best solution to an unknown problem, but that it offers certain benefits that make it worth investigating at least. In the end it might cost too much or the dispersion might be unacceptable. If we're considering auto-change barrels on an MG3 or various exotic calibres, why not?