This extract, from my Regiment's Battle Report for May 23rd 1944, is relative:
"It is interesting to note that both the Churchill 6-pounder and Sherman 75 mm. easily penetrated the Panther turret and that the Besa not only penetrated the two shields of the 75 mm. anti-tank gun but also killed the crew." Side or front, it made no difference.
In Tunisia, 6-pdr A/P (both ground and Churchill mounted) penetrated and knocked-out Tigers, some frontally. Consequently, one wonders whence came the facts to produce such statements as it took eight Churchills to destroy a Panzerturm. At the Gothic Line, with the arrival of the more efficient 6-pdr ammo, the task became even easier.