M16A2 rear sight

[SGDM]

What does one click of the A2 rear sight elevation wheel equal in MOA or inches.

We are shooting M16A2's, BH match 77 grain 2750 fps for the U.S. Army Small Arms Championships and I am trying to cipher the elevation clicks for this ammo out to 500 m.

Thanks

Greg

[pisgahrifle]

On most factory A2 guns I believe its 1/2 MOA.

[kellyn]

Supposed to be 1/2 MOA but I've found that most stock A2 sights are 3/4 MOA.

[rhino]

The marks are supposed to be calibrated for M855 ball ammo too.

[pisgahrifle]

I know that Eagle Arms/Armalite drums are 1/2, but I can't vouch for the others. The Bushie drum on my M4 seems like it could be 3/4 MOA some days....

[DogmaDog]

Huh,

According to my USMC marksmanship instructors, "one click of elevation on the rear sight will move the strike of the round up or down 1 inch at 100 yards"

so 1 moa clicks for elevation, and it's 1/2 moa clicks for windage.

You can get (supposed) 1/2 and 1/4 moa elevation knobs, with more little detent holes in the bottom.

Kellyn may be right though, if he's done the empirical work to figure it out.

And the numbers on the elevation knob are for range in hundreds of meters, for M855 ball ammo, as rhino says, but the clicks are all the same size.

You could just zero the weapon at each yard line by counting clicks up from the bottom, or you could make reference to the numbers, and start at "8/3 -2" for the 200 m line, and go to "5" for the 500 m line. But who knows how well that will work for your ammo?

Do you have any ballistic data for that ammo? Or will you have the opportunity to zero it at several ranges?

DogmaDog

[pisgahrifle]

Huh,

According to my USMC marksmanship instructors, "one click of elevation on the rear sight will move the strike of the round up or down 1 inch at 100 yards"

so 1 moa clicks for elevation, and it's 1/2 moa clicks for windage.

You can get (supposed) 1/2 and 1/4 moa elevation knobs, with more little detent holes in the bottom.

Kellyn may be right though, if he's done the empirical work to figure it out.

According to Armalite both windage and elevation drums are 1/2 moa- at least on my A2.

Accuracy Speaks and I believe White Oak Precision offer complete 1/2-1/2 and 1/4-1/2 rear sight assemblies. As far as I know both the USMC and USAMU teams are using 1/4 wind, as well as many of the leading service rifle competitors- gives you a bit more fudging room.

We've left the poor front sight out of this as well. I don't have the book handy, but if I recall right most all A2 fronts are 1-1/2. I think the A1 may be 1 1/4, and most are smaller in diameter already- this lets get a shad finer on the front end, and works well whether you're shooting six o'clock or navy- though I'm not sure if they'll thread in an A2 gas block. I don't see any reason why they wouldn't, though I'm to lazy to swap mine and go re-zero. If you like the look, though, Derrick Martin makes a .050 and .055 round front post for an A2 that's service rifle legal.

[SGDM]

After many phone calls and some higher math utilizing my toes I found the answer to my demise and confirmed it on the range.

Elevation knob - 1 click = 1.375 MOA or 1 3/8". Only an American made battle rifle!

Thanks fellas

Greg