Come to the TA, bring a friend, go to any field but A1 (GV's disabled there)
Up an osty, get your friend to up a plane.
Control Tab (enable friendly lock)
Point gunsight at him, hit tab, you now have the LCG (lead computing gunsight)
Get him to make passes directly at you, then slowly start making passes off to the side. You'll learn its not hard at all to hit in the ostie if they are comeing AT you. Leading them from the side its trickier, but doable. Its more about learning how far they are so you can estimate lead.
PS I don't zoom all the way in either, but I do get my head up above the osty sight.
Pull osti sight up so you have clean background. Put mouse pointer tip so its right on the center dot. Hit H to lock mouse. Page up max and save view.
If you need to recenter, just hit home, you'll be back to default gunsight view.
Now CALIBRATE this by picking water tower, building, shed, tree about 1k out.
Put the mouse pointer on target, fire 3 - 5 rounds and see where they hit.
If they are centered on the tip of the pointer you good to go. If not, home key, unlock mouse and adjust.