I have just the opposite experience offline. IMHO Much easier to one shot a tiger turret. With the IL-2.
One shot damage goes to the HurriD. However, the HurriD has only 15 shots compared to the Il2's 50's. The HurriD will also recoil off target after one shot, while the Il2 barely flinches. The Il2 also has a much higher ROF.
Pass for pass though, the Il2 has it hands down. It can easily land 3-4 (6-8 rounds) hits at convergence range per pass, more if the pilot pushes it and fires closer than convergence range.
My main mission flying is Close Air Support, specifically focusing in on tank killing. Killing with the HurriD is an art. It's very difficult to do. Now any goober can up and take out 2-4 tanks without really breaking a sweat. I think it may need to be perked, though lightly. Else it will pretty much just be the end of any GV missions that ups without full AAA support.