Chinese researchers claim to be able to disable US tanks with fast-moving ball
pubs.acs.org> They found that a solid sphere, weighing 20kg [...] at about four times the speed of sound [...] 25 megajoules.
For comparison, the projectile from a US M829 tank round [0] involves a spike with a mass of 4.6kg traveling at an (initial) speed of mach 4.59, or around 5.70 megajoules. The propellant and all the other stuff which stays behind brings that up to 18.6kg.
I assume this cannonball's dramatically higher projectile-mass is needed in order to make up for accuracy, so that a glancing hit still rattles everything enough to make a difference.
It's like a modern cannonball. They say a 20kg "solid sphere" traveling at 4x the speed of sound could disable a tank by exerting forces on bolts that connect the pieces together, but otherwise leaving the tank with the appearance of being mostly unharmed.
For comparison, modern anti-tank sabot impactors are roughly 1/5th the mass (and kinetic energy) and travel at similar velocities.
So if they've shown you can bludgeon a tank rather than puncture it, I'm not sure how useful that information will be when it involves ~5x the propellant and a correspondingly bigger round/barrel/etc.
Chinese researchers can claim this, but realistically, the US is one of the only countries that has repeatedly deployed its current tanks in a war context. If you don't have experience with tanks in a war, you'll very quickly learn what matters.
It's made out of LK99?