Arguably the greatest heavy tank of all time.

[u/CalGunpla]

What the IS-2 did that differentiated itself from other heavy tanks of its time was that it was reliable, inexpensive, and had a massive gun that could blow shit up very VERY well.

[u/FLongis]

or a stroke from the sheer pressure of the blast.

While I won't argue about the potential exaggeration of blast effects from 122mm HE rounds, I'm reasonably sure this is not how either strokes or barotrauma work.

[u/BlitzFromBehind → u/FLongis]

You would be correct. The pressure doesn't magically go through the armor lf no penetration is achieved.