On Il-2
a) IIRC up to early 44 the produced Il-2s had wooden rear fuselages and maybe wooden outer wings too. So 190 with its four 20mm cannons could simply shot the rear part of Il-2 to pieces. One other way to down Il-2 was to attack from side shooting at wing root, AP rounds of MG 151 should be able to penetrate there if the angle wasn't too acute and ignite the plane because there was a fuel tank there. So Il was a hard but not an impossible nut to crack.
b) At first Il-2s were a problem to 20mm AA but using 50/50 mix of Minen and AP rounds that was overcome. Same to Finns, the number of Il-2 CLAIMS of the highest scoring 40mm and 20mm AA batteries were appr. identical.
Juha
a) IIRC up to early 44 the produced Il-2s had wooden rear fuselages and maybe wooden outer wings too. So 190 with its four 20mm cannons could simply shot the rear part of Il-2 to pieces. One other way to down Il-2 was to attack from side shooting at wing root, AP rounds of MG 151 should be able to penetrate there if the angle wasn't too acute and ignite the plane because there was a fuel tank there. So Il was a hard but not an impossible nut to crack.
b) At first Il-2s were a problem to 20mm AA but using 50/50 mix of Minen and AP rounds that was overcome. Same to Finns, the number of Il-2 CLAIMS of the highest scoring 40mm and 20mm AA batteries were appr. identical.
Juha