How to zero at 50 yards using M&P Sport 2 sights

[Tazumi]

Hey everyone, I'm trying to understand the MOA concept with iron sights on the M&P 15 Sport 2 and it's a bit overbearing and confusing. My LE and military buddies are throwing me off so I figured that I might get the answer here.

I'm trying to crunch some numbers for the darn thing. It comes with a Magpul MBUS rear sight and an A2 post front sight.

Skipping a bit, after some number crunching, I came to this:


If 1 MOA=1 inch at 100 meters:

MBUS Rear Sight

1 windage click equals:

.5 MOA at 100 Meters
OR
.5 MOA at 109 Yards

100y/109y x .5 MOA = .458 MOA at 100y (It seems that it's still .5 MOA)

Divide that by 2, that's pretty much .25 MOA at 50 yards.

I hope the math is right on this one. Now to clarify.

Does this mean that for my windage, if I want to move to the right or left by 1 inch, I click 4 times?

If this is the case, I can calculate the A2 front sight post with no issues.

I would like to know the basics of calculation rather than relying on a target with blocks I can count.



What's also throwing me off is this Youtube video of a guy teaching you how to zero at 50 yards. The shot placement at 5:23 clearly shows that it's at least 3 inches from the center, but he's clicking 6 times. By my calculations above (that might be wrong of course), that's only moving the sight 1.5 inches to the left. Am I seeing something wrong? Oh man, and he's only clicking 2 times when he's adjusting elevation when it looks like about 12 inches above the center (start at 3:41). Thank anyone and everyone in advance for helping me.

https://www.youtube.com/watch?v=934LFFsC5Dw&index=2&list=LLGkV6PC6qCkTCrC5gInja6A

[XDJYo]

From your screen name, I'm assuming you're Japanese. From one Japanese to another, I think you may be over thinking this a bit too much. Put your slide rule aside, buy some ammo and get to the range.

Shoot a few warm up shots and get to work. Reid's tips on zeroing your rifle are solid. It's what I did on my M&P 15 Sport II.

Do a few clicks to get yourself closer to the bullseye. Shoot another 3 shot group. Click some more. Don't move your point of aim though and don't chase your shots. Continue to aim at the bull.

Once you get to putting three shots on the bull. Rest. Lather, rinse, repeat.

It doesn't matter what the mathematical equation it is. It depends on whether or not you are putting shots on target.

Enjoy your new rifle. See if you can meet up with some fellow calgunners and if they will give you a few pointers in exchange for a beer or two afterwards.

I'm a relative novice, so I know more experienced voices will be along any moment now.

Happy shooting and be safe.

[kcheung2]

Your concept of MOA is wrong. Minute of arc is a measure of angle. 60 minutes make 1 degree, 60 seconds make a minute. So 1 MOA is 1/60 of a degree. .0167 degrees is .0167 degrees regardless of distance.

But I agree that there is no substitute for actual range time.

[penguin0123]

1 MOA = 1" @ 100yds
1 mil = 1cm @ 100m

Roughly. Both are angle measurements so the values above are rounded. And to confuse things, there is mathematical miliradians and shooting miliradians. Unless you're sending a 16" shell across 20miles, don't worry too much about it.


If you are 1" low @ 100yds, you are 1MOA low.
If you are 1" low @ 200yds, you are 1/2MOA low.
If you are 1" low @ 50yds, you are 2MOA low.


One more thing to consider. Distance from rear to front sight (i.e. sight radius) changes the # of MOA each click represents. On M16A2, each click is 0.5MOA. On M4 with detachable CH, each click is 0.65MOA.



Don't worry about the math. Just shoot the bloody thing and walk it in.

[CSACANNONEER]

! minute of angle is one minute of angle at any distance. A "minute of angle" is not a measurement of distance. It is a measurement of an ANGLE.

1 moa at 100 yards is approximately 1"

1 moa at 50 yards is approximately 1/2"

1 moa at 500 yards is approximately 5"

[Joseph Lee]

<snip>
Does this mean that for my windage, if I want to move to the right or left by 1 inch, I click 4 times?
<more snippage>

Yes.