For some guy related reason, I watch videos like this popcorn in hand, because there’s apparently some underlying fascination with anything to do with construction/destruction in the male dino-brain.
All manner of things get very satisfactorily destroyed in these types of videos, and by now, all viewers know the drill, and what to expect.
Well, not this time!
Impressed!
I like these videos too, for the same not-quite-clear-to-me reasons.
Not quite surprised by the AR500 steel. It’s tough stuff. 5.56 XM193 will still pockmark it pretty good though (velocity is a killer), and the thinner .5" plates I have to be careful not to shoot them closer than 50yds or there’s a chance it could zip right through.
The failure mode of the cones was absolutely fascinating to watch. And the fact that T-34 armor was apparently made of hardened butter. Neat!
I have seen that “Epic” moment happen for real … back in my youth I worked for a company called ESAB
they made welding equipment and consumables, I worked in the quality control laboratory… On the fateful day in question we were asked to squish some 10mm core wire for testing. to do this we had a 150ton hydraulic press and some hardened steel press plates … well we got to work, the first was no problem it squished nicely at about 25-30 tons… the second sample was put in the press and i turned the dial, it got to about 40ton and the top press plate exploded, all i saw were sparks were pieces of the plate were hitting the supports of the press… later that day we noticed that a fluorescent tube about 30 feet from the press was out … it had a neat hole punched cleanly through it without shattering.
that was the last time we did that 
the old tank armour was RHA (rolled homogeneous armour) sometimes they would surface harden it, but i think it mainly worked by deforming and taking the energy out of the projectile that hit it, if the plate is too hard then it would become brittle, so you have to walk a fine line between too hard and shattering or too soft and not slowing the projectile down
Correct - Leopards were constructed of RHA. Still used today as the outer layer of composite armour. When talking about the performance of anti-armour weapons and protection of composite armour the unit of measure is in ‘RHA equivalent’.
e.g. this APFSDS will penetrate the equivalent of 1.5m of RHA. Gets a bit trickier with composite armour protection values because the same armour might provide the equivalent of 2m RHA against kinetic energy (sabot) rounds but only 1.5m against chemical energy (e.g. HEAT) or vice versa. That is why a lot of MBTs these days have modular armour and it can be tailored to the greatest threat, KE or CE rounds.
And you can always slap on some ERA … but with all these extras weight would probably become the limiting factor
Another fun fact with cold war tanks: Leo, Chieftan, M60 and early M1, T64, etc.
NATO countries used SABOT as the main anti-armour round so they prioritised armour protection against KE rounds because they assumed the Soviets would do the same.
The Sovs on the other hand - their HEAT rounds were more accurate (technically lower dispersion) than their SABOT rounds so they they prioritised armour protection against CE rounds because they assumed NATO would do the same.