Rather than fielding more powerful direct-fire weapons for MBT’s, I wonder how effective short barrel 155mm guns indirect-firing rounds with guidance packages like ATK’s PGK at the tops of opposing tanks would be. The notion that you have to completely penetrate the most well protected parts of a tank to render it inoperable as a tank has always been very curious to me. If you set it on fire using WP airburst, knock a track off the tank, damage the main gun, or optics and radio antennas, the tank may not be a complete write-off but it’s no longer a functional tank for the rest of the engagement. Infantry can easily finish off any tanks and tank crews that have their guns or optics rendered inoperable using hand weapons and fire.
Tanks were always supposed to be fire support weapons for infantry to use to gain positional advantage over their adversaries. If tanks could use HE shells to functionally disable opposing tanks and also provide fire support for infantry using HE or cannister shot rounds, that’d doctrinally follow the stated reason for fielding tanks unless the tankers are completely intent on carrying out tank vs tank duels.
Get rid of the ridiculously over-sized turrets by moving all crew members to the hull just like the M1 TTB and T-14 Armata. Heavier armor can then be applied to the hull without any weight gain. Use an autoloader for the 155. The US and Germany already have models that actually work. A tank like the T-14 will still be able to render a Challenger inoperable, but the Challenger would also be very effective against MBT’s like the T-14, infantry, and field fortifications. The bonus would be that we could stop fielding expensive KE rounds that are only used against other MBT’s. The cost savings and commonality advantages with artillery is worth a quick test to see if precision HE rounds direct or indirect fired at the tops of MBT’s can functionally disable MBT’s.