I zeroed mine at 50 yard and I was not expecting rear sight to move this much. How off is yours from center?
Hey Skang, I spent 8-yrs. in the Army, taught BRM as a Drill Sgt. and have handled HUNDREDS of individual M16's. I have seen much further windage drift adjustments on fixed carry-handle equipped rifles going to the left OR to the right, so I don't think yours is out of the ordinary, especially for a pic. rail mounted sight. My "nearly mint" Colt AR15A2 Sporter-II HBAR with A1 version rear sight (I picked it up in '87-'88ish while stationed in Germany) is drifted to one side of center, and I can shoot your eye out with little difficulty... you'd just have to hold still for a second... deal? On a further note, if you were to let someone else zero that rifle to THEM, it would most likely be in a different spot from where yours is atm, then if you were to pick it up and shoot it, it'd be off the POA for YOU. Strange thing... personal zeros on weapons.
I have one that's off more than the first one posted. As long as you can adjust the windage to zero it, it's within spec.
I read acceptable range for mil-spec is 10 clicks either way, which is about 3rd ling from the center.
This has nothing to do with whether or not the rear is centered. It has everything to do with the relationship of the front sight to the rail on the receiver. Even fixed front sight towers are never perfect. It is not uncommon for the front sight to need "adjustment" via a lead hammer. Even in the situation of a full rail and two flip ups the front rail is sometimes not perfectly aligned to the upper. As long as you're on at 25 yards and 100 yards left to right you're good to go.
Download a copy of the 23&P manual. It well show you how to properly adjust the front sight for correct centering of the rear sight.
Good to know I thought it was always just my builds!! Also The 23&P manual I found only says to clean and lube the sights and nothing much about the front post, would you mind linking the manual you speak of. Thanks