Questions about the G91 R1

I figured I may as well get a start on the new air tree for Italy and started with the G91 R1 (my first time using it since it got AA nords.) Now 9 times out of 10 if I fire these in a head-on and it air-bursts on the enemy I don’t even get a hit or anything they just get away without a scratch, is this normal for them?

My second question is, is there an actual reason you lose your left gun when you use these or does gaijin just want Italy players to hate life more than they already do?

I assume the aircraft was fitted with a guidance system for the missiles and thus removed a gun for room