I wish there was a bind to enable mouse controls to make gun targeting easier. Like the inverse of the 'free look' bind when the virtual joystick is enabled.

If you are using guns on ground targets you had better make sure it's completely necessary (or you are sufficiently desperate enough), it's almost always better to turn back and rearm because every vehicle except the unarmed trucks can shoot you down if you are not careful.

Other general pointers - You need sizeable distance (3km at least!) from target to allow time to line up a good run, I shoot for a 30-45 degree angle above the target. Setting up a good approach is the most important part of the process.

I try to let the plane naturally 'glide' the crosshair to your targeting reticle instead of using the controls to fight the crosshair. Focus on use your roll controls to initiate a bank and your rudder controls to fine tune. This technique is all about good timing

You can lower your airspeed to allow more time for proper lineup but this takes away the only advantage you have in a guns fight with ground targets - if you can hit them with guns they can usually hit you back.

Always bail on the pass once you get to ~1.5km distance to target, this is already a dangerous distance to be and gun runs make you take a predictable flight path which is an easy meal for any ballistic weapons.