Well, I managed to kill a Lancaster with the E-4 last night.
I had half my cannon rounds left and flew a sector out to get in an extended fight with a N1K (5 ish minutes). Even though my E-4 owned him, I couldn't connect with the remaining cannon rounds. I tried tracking shots from his close six and various snapshots. I finally ended up running out of cannon rounds, pinging him up with my bb's and calling in a countryman who had been standing by (but staying out of the fight) to finish him off. I got an assist.
I can see I still have work to do with the gunnery in this ride but it's a sweet little turn fighter. The biggest downside is it's lack of roll response at speed, but a bit of rudder helps that out. It's not as bad as the Spit I.
Oh, and as an added bonus I got to watch a P-51D run from me like a schoolgirl before I got into it with the N1K.