Another Idea. (there go the beepers:)).
The "rubber bullets" are such a transient problem, that it is very hard to test. How about a target in the hanger (They did test their guns in WW2 after all). It would give us a packet count fired, and hit. If we suspect a problem. We could test the next time we were on the ground. And relog if something was not right.
I Sort of visualize this target being set up on a remote computer, as if it were a player. We could have more then just our side of the equation.