I agree that we don't need the 45mm gun in the Armata tanks as they will work closely with IFVs that have 45/57 guns, and also it might be difficult to install two autoloaders in the tank, so it's better to separate these guns between two vehicles. Instead of the 45mm gun, I’ll install the 2A42 30mm gun or the 2A72, and the Kord 50cal as coaxial.
The 30mm gun has 2 ROF, low: at 200-300 RPM, and high: at 550-800 RPM, the gun accept 2 type of different ammo like AP-T and HE-I, and has effective range of 2,500 meters.
These two guns will be installed externally on the right side of the turret. A 30cal will be installed in the turret as coaxial for the 125mm gun.
All those guns will be operate by the gunner, and will give him a wide range of weapons that he needs to engage any target.
1. 125mm against tanks and IFVs.
2. 30mm against APCs.
3. 50cal against light armor vehicles.
4. 30cal against infantry.
In the photo below we can see the turret of the T-64 tank, with GSh-23-2 on the right side of the turret, 50cal on the left side, and vision system between them.
I’ll replace the GSh-23 with GSh-30-2K. This gun has two ROF low: at 300 RPM, high: at 2,000-2,600 RPM, Muzzle Velocity: 960 m/s, and effective range: 2,500 meters. The 50cal will be replaced by 30cal.
The reason for the 30mm gun and not the 23mm gun is that the 30mm has a bigger warhead, a better range, faster MV, has a smart fuse that can be programmed, by the gunner, to detonate above the target.
The biggest enemy of the tanks in our days is not the enemy’s tanks, but the ATGMs and the RPGs. One of the weapons that we use against them is the APS. The APS consist of radar that detects the treat, and interceptors that will destroy the treats. The radar can also find the place, from were the missile has been launched, feed this info to the 30mm gun, that will open fire against the target automatically. In one second of fire it will drop 40 rounds that will explode all over the target, kill the fire team, destroy the launcher, and than the missile will get lost.
The Armata tanks are the first tanks and concept that is design and manufacture, in big quantities, in this decade from the ground up, and it needs to answer two major questions:
1. What kind of weapons the tank will carry.
2. Who the going to defend itself from ATGMs and RPGs.
IMO the tank needs to have the capability to do 3 things:
1. To attack the team that launches and guides the missile.
2. To destroy the connection between the missile and the launcher unit, as the missile is leaser beam riding.
3. To use APS to intercept the treat if it get close to the tank.
For the 1st line we need a gun that his round has high MV, high ROF, and big warhead. The gun that answers this requirement is the GSh-30-2K
For the 2nd line we need to have a system that can deliver big amount of smoke in a very short time. One of the weapons that can do that IMO is a rocket like the 127mm Zuni. In the USA this rockets come in pod that hold 4 rockets. We can install few pods like that (see picture) on the right side of the turret.
Those rockets when they will launch toward the launcher, they will create a big cloud of smoke, that will block the connection between the missile and the launcher, and the missile will lost his the riding beam and get lost.