Someone was kind enough to give me a copy of a 300+ page document about the Hs 129, units, tactics and pilot memoirs. It included descriptions of attack tactics even for the Ju87-G2 since the Hs 129 and Ju87 G2 were under the same tactical command group in Russia performing the same support role.
Against T34 and other Russian heavy tanks the cannon tank hunters never dove in because just like we auger or ram the tank, they had the same problem in WW2. The MK101 and BK 3,7 were not effective at penetrating side armor or turret armor outside of about 100m. But, at 90 degrees to the plate could penetrate inside of 100m. Very often the Hs 129 pilots would hold fire until inside of 100m. The tank crew was simply cut to pieces, not as often an explosion or fire unless the attack was from the rear into the engine or setting off ammo. Tanks were relatively small targets for a guns kill even from the side. So only the best pilots attacked the smaller profile rear.
Guns attacks for both the Hs 129 and Ju87 were from less than 100m alt with tactical limitations. A straight run up for precise aiming at a shallow angle to account for the slope of the armor, the view limitations in aiming the guns, and pulling up before colliding into the tank or snapping the plane's rear end off against the turret. Even with the BK 7,5 the Hs 129 pilots flew in some cases only a few feet off the deck and shot inside of 100m at tanks. There was no jinking around to confuse the commander or gunner on the optics, or circling around at 3k to dive almost straight down to avoid the main gun's highest angle.
The MK101 and Bk 3,7 with carbide core rounds had no trouble passing through the armor of T34, KV-1 and KV-2 inside of 100m. This dictated the attack tactic which was never higher than 100m with a straight run up to the target. The two greatest dangers were Russian ack and small arms gun fire in and out from the target. And not pulling up quickly enough which required particularly well practiced timing to get close enough for the main gun to be effective, then pull up and miss colliding with the tank.
One Hs 129 pilot with BK 7,5 to get at a tank, flew down a building lined town street a few feet above the pavement and killed the tank with a shot inside of 100m. The Hs 129 pilots of WW2 were the A10 pilots of their time. Hs 129 never got above about 3k during the war. Many of their sortie were flown only feet off the ground.
The MK101 carbide core round could penetrate 30mm of armor from 200m. Inside of 100m it penetrated the 78-85mm T34 turret. At 1000m the BK 7,5 carbide core round could penetrate 94mm(3.5in) of armor, but the Hs 129 pilots used it with the same 100m tactics they were trained with the MK101.
The common theme on the eastern front for killing tanks from an Hs 129 or Ju87 G2. Was a straight run at the target to facilitate precise aiming at close range. Russian tanks except for the very rare documented cases, did not swing the turret main gun to face these planes and shoot them out of the air every other pass like happens in AH now. There were not very many of these aircraft, and they would have been pulled from service if tanks could accomplish that feat. These planes slaughtered the tank crews with one or two precision aimed rounds or knocked out the engine. The Russians when they could, accompanied tanks with mobile ack of all kinds because of how effective the German tank hunter air units were.
Very few MK101 or Bk 3,7 shots caused outright fires or tank explosions. The explosion was the result of setting off the tanks ammo or secondary from a fuel fire. And happened more often with the BK 7,5. Early on with the MK101 the pilots didn't understand they were killing tanks because of the lack of smoke, fire or explosions. Even while seeing the hit sprites they were taught meant a penetration strike. The carbide cores of the smaller 30mm rounds penetrated the armor breaking apart into high speed fragments along with some of the tank armor and acted like a metal storm shredder inside the enclosed space.
In all the Hs 129 was a highly effective tank killer once the tactics were established, along with the Ju87 G2 which suffered from a lack of armor. There just were not enough of them to stop the tank numbers the Russians produced and threw at them, even though they were killing tanks in numbers every sortie.
Ruffer and Rudel achieved their kill numbers by shooting from 100m and closer flying straight at the tanks.
