I'm sure you meant "depleted uranium". It makes no sense to use non-depleted uranium for such a purpose.


T-55s have late WW2-like side armour and rear armour is even weaker. All MBTs have ballistic windows - sights, hatches, turret ring, barrel - and can occasionally be penetrated by really weak penetrators.

External equipment - including CITV and externally stored personal items - is even more generally vulnerable.

The ability to penetrate should thus not be judged by anecdotes, but by the ability to penetrate
front turret
upper and lower glacis
side turret
side hull

25 mm is quite unsatisfactory even against a T-55 if you look at these. Lower hull sides are the only large surfaces which an autocannon can penetrate reliably, and I doubt a 25 mm APDS or APFSDS could do so even at a perfect angle.


Basic BMPs are notoriously thin-walled. Their protection is APC-like; they keep most bullets, most fragments and AP mine effects out and that's about it.
Upgraded BMPs on the other hand can be loaded with so much extra protection that even 30 mm APFSDS and AT4s would not penetrate front or sides.