actually how do u guys zero a rifle? if zero wrongly how ar?
There's 2 parts:
(a) a Grouping Exercise, conducted in a regular multipurpose hall, where you "fire" a 3-round shot group by aiming at a (maneuvreable) small Canadian Bull target thrice. The latter is manipulated by your partner; you signal him on where to mark each time; he measures the distance between the "triangular" spots to ensure they fall within the permissible mathematical standard.
Failure here probably means 20 push-ups plus an angry scolding, before being sent to redo the grouping from scratch.
Success here would still - likely - result in your 3-shot grouping appearing too divergent from the "median" crosshairs on the paper, eg. too high & on the left. Then it's a case of your trainer or yourself manually "clicking" the front-sight post (for up/down) & rear-sight aperture (for left-right) to recompensate. You'll then be send to do another grouping for confirmation; the uniform attempts for recruits are usually 3 tries before he starts getting a "wowo king label.
(b) a Zeroing Exercise, conducted in a shooting range, where you fire a 3-round shot group with real bullets. Thereafter it's the same battlesight adjustment as the earlier mentioned. The tekan-ing for any dragged-out zeroing can be substantial during my time, given the hot weather & a shortfall of instructors to meet the long queues for sight "clicking" (many DIs have other range duties).
FYI Sometimes the M16 sights can be "clicked" to the max, usually left or right, but leaves the soldier nowhere near the median crosshairs. What to do then? An officer can arrange with his armskot to formally change rifles, but a common peng usually has to make-do, i.e. aim agak-agak slightly more to the left or right - at thin air - & hope it'll hit the target. I kena this for my last reservist shoot, & qualified marksman out of it! (Basically entails staying rigidly still/holding your breath when you see your 1st round knock the target down.)
The other skill I mentioned - learning to fire in day/night conditions - cannot be underestimated either. At night, in particular, you need to flip the rear-sight aperture to the bigger aiming hole. The front-sight post has an in-built luminous tip that mustn't be covered in rifle oil; if it's spoilt you'll have to improvise with chalk or (dubiously, for me) white tape. Following which it's a case of gauging the imaginary crosshairs as you take aim; it's good if you see the target collapse but otherwise you're left wondering where the round landed if it doesn't. That's why tracer rounds are quite beneficial.