Iron sight adjustments for KD's where sights adjust less or more than 1 MOA

[Ringer68]

I would like some input regarding iron sights  where adjustments made are not 1 MOA. I am shooting an AR 15 with Magpul MBUS sights. The rear adjusts at .34 MOA intervals and the front adjusts at 1.25 MOA. Not a biggie at 25 yards, but how would that affect adjustments for each 3 3 3 4 come up per additional 100 yards?

[2 clicks low]

So you want to come up 3 moa. You can:

A: adjust rear 9 clicks (3 moa)
B: adjust front 2 clicks and rear 1 (2.84 moa) I would not worry about .16 moa @ 200yds, 3/10"

Work out the math for the other distances and WRITE IT DOWN. Then tape it to the stock.

2cl

[Unbridled Liberty]

I would like some input regarding iron sights  where adjustments made are not 1 MOA. I am shooting an AR 15 with Magpul MBUS sights. The rear adjusts at .34 MOA intervals and the front adjusts at 1.25 MOA. Not a biggie at 25 yards, but how would that affect adjustments for each 3 3 3 4 come up per additional 100 yards?

First of all, remember that your MBUS's are back-up sights.  They are not primary sights.  They are the "OH CRAP" close-enough sights.  They should get the job done if hits count, but they are not target sights. 

Second of all, I am not aware of any Magpul MBUS that has adjustable elevation on the rear.  So we are only talking about the front.  So where did you get the 1.25 figure?  Friend?  Internet?  Box drill?

The come-ups 3 3 3 4 are for an M1A/M14.  You should use 2 2 3 4 as a starting point for your AR. 

The best thing you can do is get to a range and gather actual data; shoot a box drill to determine clicks-per-minute for front and rear, and then shoot sighters at distance to determine actual come ups for 100,200,300,400,500.  Then like 2CL said, write it down and put it on your stock.

I assume you are trying to prepare for a KD event?

UL

[Ringer68]

Thanks you guys for the info.

Yes, never been to a KD and want to make sure I take the right equipment. I have a couple of rifles to choose from, a .308 scoped rifle which will be easier for me to use but will tear me up a little bit more if we do a lot of shooting, and the .223 AR which is a fairly new gun to me.

I have attended a couple of AS's with the AR, which I love, but I'm still working on getting the feel for the iron sights and the fit of the gun to me, and there's not a lot of consistent info on the web about these sights. I have another AS this weekend to practice (trying to requalify on a centerfire) and I plan to switch from center mass to pumpkin on a post so I can see the targets.

I am planning on going to the indoor range tomorrow and will shoot squares to try and pin down the MOA with the info you have provided. Thanks again!

Shannon

[oladcock]

Shannon...I shoot open sighted AR's a lot. First thing you need to do is pull that front sight out, wrap some tape around the threads, chuck it up in a drill and take it down to about .040" thick. Repaint with flat black and reinstall. That in itself is a HUGE help getting that front post 4moa or smaller. Rear sight...If the aperture is too big, look at getting inserts of different sizes to see what works best for you. Or you can be a cheap sucker like me and glue a piece of black tube that comes with a WD-40 can into the hole then drill it out to your liking, for me that's also .040". That's If you are used to center mass hold...DO NOT switch to 6 o'clock unless you want to spend hours and hours of dry fire and live fire practice. You'll do fine in slow fire with time to "think", but in the heat of battle (so to speak) you'll revert back to what you are used to. I read somewhere it takes 10,000 repetitions to deprogram bad habits/prior training.

On a KD...You can work out your clicks or simply figure out your holdover/under. With a .223 and a 25 meter zero, hold close to 6" under at 100, 8" under at 200,  3" under at 300, and 10" over at 400...Depending on your bullet weight/sight height which I assume to be 65gr/2800fps/and 2.5"....O.L. 

[Ringer68]

Shannon...I shoot open sighted AR's a lot. First thing you need to do is pull that front sight out, wrap some tape around the threads, chuck it up in a drill and take it down to about .040" thick. Repaint with flat black and reinstall. That in itself is a HUGE help getting that front post 4moa or smaller. Rear sight...If the aperture is too big, look at getting inserts of different sizes to see what works best for you. Or you can be a cheap sucker like me and glue a piece of black tube that comes with a WD-40 can into the hole then drill it out to your liking, for me that's also .040". That's If you are used to center mass hold...DO NOT switch to 6 o'clock unless you want to spend hours and hours of dry fire and live fire practice. You'll do fine in slow fire with time to "think", but in the heat of battle (so to speak) you'll revert back to what you are used to. I read somewhere it takes 10,000 repetitions to deprogram bad habits/prior training.

On a KD...You can work out your clicks or simply figure out your holdover/under. With a .223 and a 25 meter zero, hold close to 6" under at 100, 8" under at 200,  3" under at 300, and 10" over at 400...Depending on your bullet weight/sight height which I assume to be 65gr/2800fps/and 2.5"....O.L.

Thank you OL that is helpful. I did consider reducing the pin as you mentioned. Glad I am not crazy for wanting to do that. Looking at other styles of pins as well.

As far as unlearning bad habits, I'm not worried about that part. This is a new gun for me and I haven't yet settled into a pattern. I ended up being happy with the POI I found at the range today which is closer to center mass than 6OH but it lets me see the top of the Phase 4 AQT target. For me this lets me acquire the target faster than I have previously and I shot good patterns.

As far as the hold positions, I'm not sure I understand the different numbers for each additional 100 yards. If I hold at 6, then 8 under, why is the next progression only 3 under and the last over? Is this compensating for bullet drop? I want to be sure I understand the logic so I know how to adapt with my circumstances when I get there. The ammo we are using is Federal 55 grain at 3240fps.

Thanks again for your input.

Shannon