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):
First:
M829
M829A1
M829A2
M829A3
M829A4
M829:
DOI: 1985
penetration at 2km, on plate slopped by 60@: 540-560mm RHA: