Your configuration of the M16A2/3 (AR-15) was designed primarily for use with iron sights. The only two optics considered as accessories for it are the AN/PAS-13 thermal weapons sight and the AN/PVS-4 night vision sight.
The additional height of mounting a day optics scope onto the carry handle creates a problem in obtaining a proper cheek weld without having to add some kind of stationary or adjustable cheek pad on the stock.
That's why the military adopted the removable carry handle version, M16A4, and more recently the M4 for their versatility.
I’m not sure which version of the Leupold VX-III you have but I can probably guess it’s about 12 inches long. Even if you went with the Leupold Mark 4 2.5-8x36mm MR/T M2 w/ Illum. Reticle (very tacticool), which is about 11 inches long or one of the old 4X AR scopes, you would still have to add some sort of temporary cheek pad.
Red dots and ACOGS are alright for close quarter work, but you still can not obtain optimum sight picture without adding a cheek pad.
Hell, the cheek pad doesn’t have to expensive or pretty. We used to use foam rubber and duct tape.
I would pass on adding any sort of optics and use the rifle the way it is to develop and improve your shooting skills.
You may also want to consider handloading your own match grade ammo for it.
The additional height of mounting a day optics scope onto the carry handle creates a problem in obtaining a proper cheek weld without having to add some kind of stationary or adjustable cheek pad on the stock.
That's why the military adopted the removable carry handle version, M16A4, and more recently the M4 for their versatility.
I’m not sure which version of the Leupold VX-III you have but I can probably guess it’s about 12 inches long. Even if you went with the Leupold Mark 4 2.5-8x36mm MR/T M2 w/ Illum. Reticle (very tacticool), which is about 11 inches long or one of the old 4X AR scopes, you would still have to add some sort of temporary cheek pad.
Red dots and ACOGS are alright for close quarter work, but you still can not obtain optimum sight picture without adding a cheek pad.
Hell, the cheek pad doesn’t have to expensive or pretty. We used to use foam rubber and duct tape.
I would pass on adding any sort of optics and use the rifle the way it is to develop and improve your shooting skills.
You may also want to consider handloading your own match grade ammo for it.