interesting reading:
A-10 combat effectiveness test, 1977
Combat Damage Assessment Team, A-10/GAU-8 Low Angle Firings Versus Simulated Soviet Tank Company (10 March 1978).
This report describes firings of the A-10GAU-8 weapon system on 10 March 1978 against a Soviet tank company simulated by ten combat loaded M-47 tanks. The pilots attacked at low altitudes and dive angles simulating operations in hostile air defense environment. GAU-8 30mm Armor Piercing...
apps.dtic.mil
A-10 combat effectiveness test, 1977