I read on another forum that Pershings and Shermans used in the Korean War had better tank ammunition that during WW2, a factor in how they defeated T-34/85's they faced. Could they penetrate any part of the T-34/85 armor then?

Yes, the 90 mm could penetrate at any angle, and the HVAP ammunition on the Sherman's 76mm had no problem penetrating the frontal armor. HVAP had been in short supply in 1944-45, but was amply available in 1950.

The Pershing crews were sometimes frustrated, as the 90 mm AP ammunition would often drill through both sides of the T-34, without setting it afire, leaving the US gunner to wonder if he'd hit it at all. They sometimes resorted to high explosive 90 mm ammunition, which could knock the turret off the turret ring by blast alone.

Thanks! I deliberately wanted to make a "knocked-out-from-the-front" burned-out tank where turret and hull just below it have been hit. I also wanted to make one knocked out and left some time ago, with a Churchill Crocodile driving past it. I assume by the time British tanks arrived, the North Korean tank forced had already been wiped out.

I thought the T-34-85 had only a maximum armor effectiveness of 90mm, so the M1 gun would penetrate it at combat ranges even using the standard AP ammunition.

A little late to the party, but:

1. The T-34/85 as discussed was vulnerable to the 76 MM firing HVAP and all anti-tank rounds from 90 MM guns. There's actually reliable accounts of bow, all the way out the engine compartment penetrations from 90 MM fire.

2. Virtually all tank on tank engagements in the Korean war happened in the opening few months, and entirely between US and NKPA tanks. The British tanks basically arrived in theater as the last of the NKPA's remaining armor was destroyed in the initial fighting.

Well, you could do a double British entry as enemy and friendly. There was an instance where a British Centurion knocked out a Cromwell that had been captured by Chinese forces and pressed into service. Just for something to think about...