.50 cal?

[Feuerfalke]

I flew the P-51 a lot and I really like the 50s in the game. You usually have to aim a bit better than with most large-caliber-guns, but they are surely not undermodelled if used correctly.

(if at all the damage-model is undermodelled and of course the pilots are undermodelled. In RL if you shreddered a plane or got it smoking, it would retreat. In IL2 it fights back until it explodes and even if it turns and runs, some a$$hat will follow even wingless and burning wracks to get the final shot in and earn the 100 points.)

The circle of the P-51 is set to a FW-190 IIRC at 175 yards. As a yard is .9144 meters, you can set your convergence at 150-160meters. Now if the wingtips of a 190 touch the sides of the ring, with the fuselage in the center, you have a maximum kill chance and it mostly is a kill with a short burst at that range.

At ranges of 300m you can try sniping. In some very stable planes like the P-38 or a trimmed P-47 you can be lucky to get a Pilot-Kill or critical hit on controls or the engine, usually though, you see a lot of hits and small debris coming off, but do little damage.
The Cal50 bullets do their damage primarily through inertial energy, they lose effectiveness dramatically over that distance and they scatter a lot more. Convergence at 300m means that a lot less bullets actually hit the convergence-point than at 150m range.