Not to mention if these were mounted on a mobil platform, it could fire A LOT of shells and move before any enemy coutner artileryfire could be shot.

2) The horsepower needed to spin up and feed a multi-barrel gatling in artillery calibres would be horrendous

3) The accuracy would go to pieces. Those guns rock about quite a bit after each shot.

4) It would probably damage the vehicle with multiple very heavy shots in a short period

5) You couldn't fit the necessary recoil mechanism into a vehicle, and it probably wouldn't be compatible with a repeating mechanism

6) 20 RPS with anything in current artillery scale (105mm upwards) is insane.

May be worth some R & D for some caliber in the light zone.  5, 6 maybe even 7 cm?  With the high volume burst, the cheaper precision guidance from the cute new fuzes with vanes, and and low launch energy/moderate range it could be worth  a look.

What about the lager caliber "Metal Storm" systems?

What about the lager caliber "Metal Storm" systems?

A gatling gun firing the 40mm rounds of the Mk 19 would be interesting. Not sure it is needed but I wouldn't want to be infantry on the receiving end of it. In an indirect fire mode it would have an impact similar to DPICM but without having to throw a big, heavy round. The range would be a lot less than a full scale howitzer but it wouldn't need all heavy a mounting due to the reduced recoil impulse. The normal deviation of a dumb round wouldn't be all that bad a thing, giving a burst some spread over the target area.

Now what about a low recoil system like mortars.  Or are the current auto loading mortars good enough?

I think that just for the weight those barrels would create would be a waste, when rapid fire single barrel guns would suffice.

Or even twin mounts.

 

How heavy would, say, a six-barrel Mk 19 be?

And would it really offer a worthwhile effect that couldn't be offered by paired Mk19s?

Or other weapons?

 

As for mortar calibers (to 50-60mm),

perhaps a scaled-up-yet-again Bushmaster gun capable of firing 60mm mortar rounds (similarly encased like the 50mm SuperShot) at higher velocities at low angles would give us more than enough effect (200rpm?), although rangewise we shouldn't expect anything greater than can be currently reached (5km w/ 60mm). Should prove hellish in the direct fire role though...although, again, why use 20-30 small rounds when one or two big ones suffices?

 

As for 70mm sized: helos have rockets for that, and if those precision kits are fitted, a given Apache has the potential of 76 (19x4) precision artillery shells (assuming a roughly 5kg warhead per rocket).

 

How big a magazine would a given AFV need to feed a high rate of fire artillery system?

Do you want high angle plunging fire capability, or is this a within-visual-range mostly direct fire system?

If the latter is the case, why not just build the 57mm Naval All Target Gun into an AFV turet with a few hundred rounds?

Half a dozen of those should be more than enough for general destruction of a lot of targets (people, trucks, mud huts, etc), although their use against heavy armor and reinforced concrete is probably marginal at best.

 

Gatling Artillery is best left to that Yuri's Revenge mod, Eagle Red (in whatever version is out now). You Red Alert 2 (Command and Conquer) fans probably get the reference.

Recoil impulse for the GAU-8A is supposed to be about 10,000 lbf. I know the recoil impulse for the M256 on the M1 is 160,000 lbf. I think the recoil impulse for a modern 155mm howitzer is almost 300,000 lbf, although the length of the recoil allowed in a howitzer may mitigate this. 

 

Estimating the recoil impulse for a GAU-8A type gun firing Mk. 19 rounds is problematic since I don't know the masses of the projectiles of the GAU-8A and Mk 19. I'm going to assume that the Mk 19 round that identical to the GAU-8A but scaled up to 40mm. In reality that is probably not even remotely valid and thus the recoil force I'm estimating for a Mk 19 gatling gun is also probably dramatically overestimated as well. My estimates for a mortar are obtained by directly scaling up the mass of the projectile from my estimate of the Mk 19, and hence are probably dramatically overestimated as well.

 

I do know that the GAU-8A has close to a 1000m/s MV, while the Mk 19 has aproximately an 800m/s MV. The contribution of velocity to the weapon's muzzle energy is about 35% less. Assuming a direct scale up from 30mm to 40mm, the round will be 2.35x heavier ( [40/30]^3 ). So overall the recoil will be about 50% greater, or about 15,000 lbf. Scaling up to 60mm with the same muzzle velocity as the Mk. 19 gives a recoil force 8 times that of the GAU-8A or about 80,000 lbf. Still only half that of the M1's M256.

 

Not quite time to go for rail mountings yet.

The ammo drums might be a bit of an issue. You could have a small one in a bustle on the gun and a bigger one in the back of a FAASV. I'd say just issue 2 FAASVs per gun and have 1 linked to the gun at all times when in a firing position, while the other could run for resupply or provide security. Ammunition expenditure wouldn't necessarily be greater in terms of total weight of rounds than for conventional artillery, but you would have the capability to rapidly deliver massive fires when needed.