AHC: Rotary Cannons as main armament for MBT-s

[Marko]

I was watching a documentary on A10 Thunderbolt and that amazing cannon of it's so I started wondering what if such weapons were used on Tanks.

Just to help you visualise http://www.games-workshop.com/MEDIA_CustomProductCatalog/m340116a_99120105045_IGPunisher_873x627.jpg (I know, I know but concentrate on the cannon it does look cool)


So how would you make rotary cannons as main armaments for Tanks (and possibly on APC-s) and what would be the earliest date after the introduction of the tank that such a thing would be possible. Also what do you think would be butterfly effects of such a set up.

 

[Easterling]

The rotary cannon of the A10 can not penetrate the frontal armour of modern tanks.
Such a weapon may be suitable for something like the BMPT but not for a true tank.

 

[Rubicon]

Like this?

 

[Shaby]

I wrote a long reply, but lost it. Anyway, what he said. Besides, aiming one projectile is a lot easier than a hundred of them. Rate of fire of the GAU cannons eats ammo quickly. And so on.

 

[Aelita]

The rotary cannon of the A10 can not penetrate the frontal armour of modern tanks.
Such a weapon may be suitable for something like the BMPT but not for a true tank.

And frankly, it's efficacy on the rest of modern MBTs is doubtful as well. It would shred their tracks quite nicely, but I doubt it could reliably penetrate the rear deck of a modern NATO MBT.

 

[Gryphon]

I wrote a long reply, but lost it. Anyway, what he said. Besides, aiming one projectile is a lot easier than a hundred of them. Rate of fire of the GAU cannons eats ammo quickly. And so on.

That's the biggest problem. You can put a hundred shells of various sorts into a tank's ammunition storage. The A-10, despite the ammunition barrel occupying a huge portion of the airplane, has only enough ammunition for a few seconds' continuous fire.

Add to that the immense stress of firing the bloody thing- an A-10 flying at four hundred miles an hour can be slowed to a stall (really impressive, considering it was designed for low speeds) if it shoots too long, so imagine how much pressure that'd put on a vehicle- if it's light enough, firing the gun might well flip the thing over, or if the turret is not securely fastened, might well rip the turret clean off.

And that's in addition to the other objections herein presented.

 

[Marko]

Like this?

That look interesting but I was thinking bigger.

 

[CalBear]

One significant problemis that the GAU-8, which is, AFAIK, the most effective anti-armor gatling type gun in service, has an effective anti-armor range of 1,200 meters, and, as has been noted is not capable of penetrating front hull or turret facing armor of a modern MBT. The 120mm gun on the Abhams has an effective range of 4,000+ meters and will slice through anything except another Abrams or Challenger II's front plate like an icepick hitting a mylar balloon.

The 120mm system will get 90%+ 1st shot kill at max range, fires between 6 and 10 round per minute (depending on the tank crew). At top speed it would take a MBT armed with a GAU more than 2 minutes to reach maximum range from the time that the 120mm could engage. That means one Abrams (or Leopard, Black Panther, etc.) could engage and destroy the better part of two attacking tank companies before being exposed to ineffectual counter fire.

That makes the hypothetical GAU armed MBT a rather poor return on investment.

 

[Marko]

I understand that todays MBT-s battle cannons are superior to GAU-8. What I am interested if it is possible the have rotary cannons as part of the Tank evoultion rather than single shot cannons and how would that affect battlefields etc...

 

[Shaby]

The problem is that armies operate on 'most bang for the buck' principle. Bigger cannon, more bang for less buck when you factor in munitions.

Second, unless you retard armor development so that bigger cannon is not really necessary it might be marginally possible. How does that happen I just cannot imagine.

 

[bsmart111]

I'm surprised no one has mentioned recoil as a problem. Rapid fire guns generate a huge amount of recoil. Absorbing that in even something as heavy as an MBT is difficult.

Heat dissipation is also a problem. the airflow over a moving platform such as an A-10 provides a constant new supply of air around the gun barrels.

The high rate of fire is needed for an aircraft which may only have a couple seconds when the target is lined up. With an MBT the firing solution changes at a much slower rate so they have time to select the proper moment to fire the one killing round.

 

[Corbell Mark IV]

Perhaps widespread adoption of cheap armored cars?

So that there are actually few real tanks to be targets...

Mmm, no Cold War, or a SOviet Pact that, for some reason, mistakenly, is led to believe that a insanely massive zerg rush of lightly armored, and armed APCs is superior to a relatively less massive tank horde.

Just the seed of an idea, I know it needs more.

 

[Aelita]

I understand that todays MBT-s battle cannons are superior to GAU-8. What I am interested if it is possible the have rotary cannons as part of the Tank evoultion rather than single shot cannons and how would that affect battlefields etc...

I don't know if the GAU would have been effective enough, even when it was first unveiled. Standard Warthog tactics involved attacks from the sides and rears for a reason. Even with the added 150+ m/s of velocity due to the Warthog's forward speed, the GAU-8 couldn't reliably penetrate much more than like 75mm of RHA at 500m. An M46 had 102mm of frontal armor, pretty decently sloped too.