About tank guns and amunition, hope it will be interesting topic :-)
In penetration data I will base on russian sources -they are ussaly most credible (the best). I will ussaly give value for monolith steel plate slopped on 60@ - it's the best scenario for APFSDS penetrator. In sucht scenario (slopped on 60@ plate) penetration value can be bigger at even 17-20% then on 0.degree plate - this is caused by "asymmetry loads back surface" of the plate):
New here, but I've followed this thread (and Mech Warfare) for a good while.
I attend the United States Military Academy and it is branch week here. Armor brought an M1A2 SEPv2 which, while awesome and cool to get inside of, was nothing new. However, they had a cutaway of a M829A4 round, which was on public display so it's not breaking OPSEC. Thought it would interest you guys.
Edit: I have no official measurements but I've looked at some photos of M829A3