Grizz,
There should be a 'weapons' folder in the .zip, containing a .xml with the round. I 'll attach it again.
Apparently CFS3 does not allow for player-fired AA rounds with proximity fuses. So there's no smoke puffs etc. Tracer is set at 100%. You have to score direct hits in order to bring down your target. Try shooting ground targets first to check that the gun is actually firing shells. And then again, you have to learn how to use the gunsight. It's not easy to hit a flying target: There's a lot of lead involved. Try to make the target fly towards the center of the gunsight, using the lines. The rings tell you something about the lead. The more perpendicular the aircraft is flying in relation to your position, the more lead is necessary. Even up to the point where it is outside the outer ring. Remember that you are firing over a greater distance than when you are dogfighting; by the time the shell gets there, the target could be gone. A clue is provided by the tracer: If you see it passing between you and the target, there's not enough lead. If you see the target passing between you and the tracer, you're giving too much lead. It really requires some practice but fortunately, Ju-52s are slow. If you get the hang of it, switch over to fighter aircraft: Smaller and faster targets!
Let me know how things go for you.
;-)
Frosty