I just flew a few mock fights in a Hurri Mk1 against an AI 109E-4 in QMB, and...
I won all of them eventually, but only after damaging the 109 in an almost head-on pass enough so that I could catch him. Thank god for those glass-jaw DB601As
Frustration is the word I think, since the fight always went like this: I dodge the first head-on pass, after which both turn. I easily get on the other fellas tail but too far to effectively open fire. He starts a shallow turning climb to get away, which is impossible to follow. I straighten out and put the Hurri into max climb while watching the other fella. When he sees I've given up the chase he pulls up into into vertical and does a hammerhead. Here's your chance: If you turn back towards him immediately after he starts the hammerhead you'll get a nice shot from above when he's coming down. After this he'll extend, you'll turn after him and the chase is on again...
Edit: If you want the better modded gunsight reticles, go to your IL2/MODS folder and remove the "-" in front of the "BritishReticlesMod" folder. It's disabled by default.