Oh, I also heard of some or other american experimental tank in WW2 that had the features I'm trying to describe. Any one know about this?
@GunBunny. Yeah, Wirblewind/Ostwind Flakpanzers, but those aren't really what I'm looking for.
As for enginering issues.
Well obviously your eithing going to have sacrefice some mobility or armour to mount a second main cannon on your tank. For one your turret is going to have be bigger to house the second gun, you don't really need a human loader, auto loaders are faster and take up less space so that solves that problem. The larger turret is going to be heavier, so speed is going to compromised, or if that isn't an option, take off some armour.
Stronger recoil can be conpensated by stronger engineering. But over all it's going to be more expensive than a regular tank, anyway you look at it.
Pros: Double firepower, literaly, in one of 2 manners. Fire both at the same time and you get double the punch, or fire them in rythm with eachother and you get twice the rate of fire, more targets down in half the time. Plus you get most of the advantages of two tanks, within the volume of one (shipping space), and less cost than two.