There isn't much you can do to protect what is essentially a very long and relatively thin metal tube from damage against anything over small arms fire.This may be a dumb question, but how are tank's barrel protected? They are made of metal instead of composites. Any hit on barrel could disable the tank.
If a tank face an IFV which the rapid fire would inevitably touch the barrel, would tank be disabled regardless of its strong armor?There isn't much you can do to protect what is essentially a very long and relatively thin metal tube from damage against anything over small arms fire.
Any heavy munitions from a .50 upwards will damage or completely destroy a tank gun barrel. And a damaged gun barrel is unsafe to fire anyway. You get to a point of diminishing returns.
An armoured barrel is possible but more weight will require more hydraulic and mechanical force to swing around and elevate, increasing warping and decreasing accuracy. And back to the diminishing returns, you cannot armour a barrel enough within reason to protect it against heavy weapons without sacrifices and extra engineering.
Even a couple CM of armour steel around a barrel can increase its weight by hundreds of KGs, cause inconsistent barrel warping when hot - affecting accuracy and only just about being able to stop a single AP HMG round, let alone RPGs ,30mm cannon and other anti-armour weapons.
Another point to consider with this in mind is that when sideways and from the rear, the gun is not visually in the body of the tank (where an enemy will try to hit). From the front, the gun barrel presents a tiny silhouette compared to the rest of the tank for an enemy to hit. Hence the low probability of a direct gun impact is not worth the above sacrifices.
What rapid fire are you talking hire Most rapid fire gun are 30mm or less but by then the IFV will be long dead !. As Sumdud said the silhoutte from the front is minuscule compare to the rest of the tank Remember Tank to tank or IFV engagement is only frontal engagement The chance that side engagement is very small Beside Tank is not alone most likely they are accompanied by the infantry either dismounted or with IFV that will engage the unfriendly IFV with either ATGM or anti tank gun or recoiless gun like Carl GustavIf a tank face an IFV which the rapid fire would inevitably touch the barrel, would tank be disabled regardless of its strong armor?
Possible but not necessarily. But to put it this way, if a tank turret is facing the IFV, the optics are a larger target than the gun barrel itself. Without optics an intact gun is useless as well. An IFV firing APDS or HE rounds can also disable the optics, tracks, sensors, countermeasures etc. It isn't difficult to mission kill a tank. Even a rifle round to the optica/sensors or a grenade to the tracks can mission kill a tank.If a tank face an IFV which the rapid fire would inevitably touch the barrel, would tank be disabled regardless of its strong armor?