The problem with the T-34s armor was similar to the same problems the Germans had with the Panther, only in reverse. The Russians at first did not know how to make adequate armor, but with the help of Allies and experimentation (and additional metallic ores) improved greatly. It also made a huge difference, during some months of the war, as to which factory was making the tank. The examples the Americans received were very early for the -85 and were from a period where Stalin was pushing for numbers over quality. This led to situations where tanks were fielded without ammunition, radios, or even more than a single crewman. It also led to victory.