Megawatt laser is still a long way to reach 10MJ muzzle energy of current gun, even with Moore law. And MW may be a trick, since a very short pulse can be very high in Watt, but very low in Joule.Look, Here is the problem Is see with this logic, A bigger tank gun needs bigger rounds bigger rounds mean a bigger magazine a bigger magazine means a bigger tank, a bigger tank means armor, which means a bigger tank gun. and so today's 50-60 tons becomes tomorrow's 70-80 tons and then that becomes 90-100 tons. at the same time you still leaving all the problems and making more. as the tank gets heavier getting it to the battle becomes harder, 50-60 ton tanks have a hard time with bridges as it, Air transport is a already a pipe dream and Amphibious is nearly the same. add to that they still rely on highly combustible charges that are a proven major weak point for tanks and any other platform that has to rely on them. As if a fire starts on the cartridges it finds a ready fuel supply and can reach a temperature to cause the ammo to cook off. blowing the tank up form the inside out.
I don't know about "Laser RPG's" but I do know this power is becoming more and more readily available Tanks and Armored vehicles are already becoming more and more computerized and those computers need more power then the tanks of the past could offer. as a result energy capture and auxiliary power units are becoming the norm. BAE at the AUSA show this year showed off a 40 ton APC with a megawatt laser. that vehicle powered by 2 generators with a electric drive had has the power to run the laser and drive. that's just the start.
Your attitude is unacceptable in military, if the real threats exist, you can not wait ten years for a weapon program. This is acceptable to the US because it doesn't need anything immediately, and can burn money for RD jobs.Rail Gun Ammo has the advantage of being inert. there is no cartridge. no propellent only the warhead. and military explosives are more stable then ever likely to be even more so in the future. It's likely not going to happen in the 2020s or maybe even the 2030's but the options are either we keep building until Super Heavy tanks like the Maus or we find a compromise.
And being inert is limited to direct fire, since indirect fire requires something explosive. I believe indirect fire is more important than direct fire, because the vast longer range.
I don't believe in binary liquid propellant, that gun must be a factory of itself. Mixing propellant, pumping propellant, leaking propellant, controlling burn rates,...Personally I think ETC guns with a Binary liquid propellent are what we will see nearer term. the tank will have unmanned turret with a larger bore then barrel. the Autoloader will select the round load and close the breach. When the commander selects the target the gunner will line up and pull the trigger. two chemicals will be injected into the chamber much like a fuel injection system on a car. one will be a oxidizer or catalyst the other the fuel both are aerosolized. then the ETC fires igniting the mix firing the round. IF the tank takes a hit from enemy fire the binary fuel cells would be separated and individually armored the turret being unmanned. The would be sitting under a armored roof in a armored compartment. the turret trashed the rounds lacking there own cartridges and the propellants being spaced and perhaps only flammable but not as hot as the two compounds the actual damage would be a mission kill for the vehicle but overall being a repairable one. the overall gun calibre itself wouldn't need a major jump the rounds would be fired at a higher velocity and efficiency well still being about the same calibre, existing round could be adapted therefor saving cost.
And it seems there is no program in any binary liquid propellant that successful?