Problems sighting in a M4 style AR-15

[WanMan99]

I have a AR-15 with quad rail setup, 14.5" barrel and a 2" brake. I have Magpul BUIS on the top rail (front and rear sight). When shooting an initial 5 round set today (first time shooting this gun) every round was approximately 3' - 4' high. I adjusted them down as far as they would go but the result is still off paper. I switched over to a cheap Barska 3x9 red dot and the result is worse (4' - 6' high). 40 rounds shot and I only got 12 on paper and this was because I aimed 3' below the target.
This is on a 50 yard plinking range with bench rest.
Question; How the heck do I get this thing to be at least close to zero at 50 yards? Both the scope and the buis have standard picatinny rail screw system and there does not seem to be a wrong way of putting them on. The adjustments seem minor but it seems I need major changes.
I am a pistol guy so my rifle skills are weak (obviously) any suggestions are welcome.

 

[Almostelmo]

Bore sight the upper first:

Take the upper off, remove the bolt, set the upper on some sandbags and look through the barrel at your target. Without moving the upper, lift your head up and look through the sights. You should be pretty close. Adjust sights as necessary.

 

[Scarab440]

is it a single Rail (Upper + free float on the same plane) or is a railed gas block?

 

[exo]

This is the second question of this type in the last week.

Try starting out at a closer distance, 25y is a good bet. Then move back further.

In both the iron sights and the red dot, what does your sight picture look like?

Are you controlling your breathing? (fire when you've completely exhaled)

 

[Knicks]

http://www.northeastshooters.com/vb...ost-above-ears-and-out-of-well-to-zero-(AR15)

 

[xtry51]

I have a AR-15 with quad rail setup, 14.5" barrel and a 2" brake. I have Magpul BUIS on the top rail (front and rear sight). When shooting an initial 5 round set today (first time shooting this gun) every round was approximately 3' - 4' high. I adjusted them down as far as they would go but the result is still off paper. I switched over to a cheap Barska 3x9 red dot and the result is worse (4' - 6' high). 40 rounds shot and I only got 12 on paper and this was because I aimed 3' below the target.
This is on a 50 yard plinking range with bench rest.
Question; How the heck do I get this thing to be at least close to zero at 50 yards? Both the scope and the buis have standard picatinny rail screw system and there does not seem to be a wrong way of putting them on. The adjustments seem minor but it seems I need major changes.
I am a pistol guy so my rifle skills are weak (obviously) any suggestions are welcome.

If your gun is shooting high with irons, you want to RAISE the front post, not lower it.

 

[WanMan99]

If your gun is shooting high with irons, you want to RAISE the front post, not lower it.

I bet this is where I am going wrong. I am lowering the front site when I should be raising it. I think I will go with a bore site laser on the 25 yard range until everything lines up and then make some trial shots on the 50yard range and try to get it dialed in. Unfortunately I spent most of the time shooting pistol and worked on this last and ran out of time.

 

[WanMan99]

http://www.northeastshooters.com/vb...ost-above-ears-and-out-of-well-to-zero-(AR15)

Thanks, that thread was somewhat helpful but I do not have an A2 front sight. Still had plenty of valuable troubleshooting tips.

 

[xtry51]

It happens. I always zero at 25 for a new rifle or sights. And make sure you're using the actual front sight post tool so you're not banging up the post.

 

[mousegunfan]

It also helps to do one adjustment at a time. In other words do elevation to completion, then windage. Especially with optics. Just curious, how close were you before you adjusted the sights the wrong way? Your in the ballpark. Just go back to 50 yards and start raising front sights. Go 2 full turns up and I bet your on the money @ 50 yards. Although that flip up may be different, but it should be close.

 

[thormx538]

Here's how I zero my new builds quickly...

1) Shoot 2-3 shots at something on the 50yd berm, whether is a dark patch of dirt, a clay pigeon chunk, etc.. That way it's easy to see where you missed.
2) Make adjustments. Front sight for elevation (follow your POI -- if it's high, raise the sight. Low, lower the sight), rear sight for windage (opposite of POI --if your POI is left of the POA, move the rear sight to the right). 1 MOA is 1/2" at 50yd.
3) Put 2-3 rounds on paper when aiming at the bullseye with the sight picture you like. Some guys cover the target w/ the post, some lollipop it. Up to you.
4) Adjust and repeat until you're zeroed.

Don't chase your zero. Contrary to what you might see on the internet, not everyone is capable of making sub-MOA groups with irons. Determine how good of a group you can get, even if the zero is off. If you shoot three rounds and they're all high-left, there's a good chance your zero needs to be adjusted. If one round is high-left, one low-right, and one high-center, don't touch the zero -- it's you, not the rifle.

Use good trigger discipline (pad of your finger, not a joint. Press the trigger, don't pull it. Don't anticipate the recoil -- let it surprise you), good breathing, and a well supported firing position (front/rear bags if you can). Use the small aperture on the AR sights.

FWIW, MBUS are not designed as primary sights. You will notice more play/slop in them than real irons. Things flex, and they aren't completely repeatable. Understand that they were not designed for you to be able to shoot a dead center group, and keep that zero after you open/close them 50 times and run the rifle through the dryer for a few cycles. If you can shoot 3-4MOA with factory ammo off of a bench with MBUS, that's about as good as it gets. The same sentiment holds true for more expensive metal flip-up sights, but they will be a bit better (more consistent, more durable) than the polymer MBUS. They still won't be as good as something like an A2 upper with a fixed FSB though.

 

[WanMan99]

Here's how I zero my new builds quickly...

1) Shoot 2-3 shots at something on the 50yd berm, whether is a dark patch of dirt, a clay pigeon chunk, etc.. That way it's easy to see where you missed.
2) Make adjustments. Front sight for elevation (follow your POI -- if it's high, raise the sight. Low, lower the sight), rear sight for windage (opposite of POI --if your POI is left of the POA, move the rear sight to the right). 1 MOA is 1/2" at 50yd.
3) Put 2-3 rounds on paper when aiming at the bullseye with the sight picture you like. Some guys cover the target w/ the post, some lollipop it. Up to you.
4) Adjust and repeat until you're zeroed.

Don't chase your zero. Contrary to what you might see on the internet, not everyone is capable of making sub-MOA groups with irons. Determine how good of a group you can get, even if the zero is off. If you shoot three rounds and they're all high-left, there's a good chance your zero needs to be adjusted. If one round is high-left, one low-right, and one high-center, don't touch the zero -- it's you, not the rifle.

Use good trigger discipline (pad of your finger, not a joint. Press the trigger, don't pull it. Don't anticipate the recoil -- let it surprise you), good breathing, and a well supported firing position (front/rear bags if you can). Use the small aperture on the AR sights.

FWIW, MBUS are not designed as primary sights. You will notice more play/slop in them than real irons. Things flex, and they aren't completely repeatable. Understand that they were not designed for you to be able to shoot a dead center group, and keep that zero after you open/close them 50 times and run the rifle through the dryer for a few cycles. If you can shoot 3-4MOA with factory ammo off of a bench with MBUS, that's about as good as it gets. The same sentiment holds true for more expensive metal flip-up sights, but they will be a bit better (more consistent, more durable) than the polymer MBUS. They still won't be as good as something like an A2 upper with a fixed FSB though.

+1 to you sir, excellent advice.

 

[mursenary4]

The scope should be relatively easy to zero. What most people do wrong is if they are shooting left, they move the scope to the right making them shoot further to the left lol. What you want to do is get the gun in a sled, or at least bench the front end. Take a shot and without moving the rifle adjust the cross hairs over the hole the shot just created. Then once your scope is covering the hole move the muzzle over the bullseye and take a shot. Again hold the muzzle in place and adjust the scope over the hole. Rinse and repeat until you are on

 

[exo]

If you're new to rifle shooting, I can't recommend Appleseed enough. At $60 for two days, it's excellent value for money.

In the interest of full disclosure, I'm an instructor in training with Project Appleseed

 

[Arto]

your can get a nice carry-handle w/National Match sight from DPMS for just under $100 -
http://www.dpmsinc.com/Detachable-National-Match-Carry-Handle_p_2131.html

then you'll get 'em all in the bullseye!

 

[Biff Quizler]

If your gun is shooting high with irons, you want to RAISE the front post, not lower it.

+1

Counter intuitive but the truth. Windage on rear sight on the other hand......

 

[Pants]

I like these targets when sighting in a new rifle. I usually set it up at 25 yards with a sandbag.

 

[ColdDayInHell]

It happens. I always zero at 25 for a new rifle or sights. And make sure you're using the actual front sight post tool so you're not banging up the post.

Bingo.

 

[mac1911]

Thanks, that thread was somewhat helpful but I do not have an A2 front sight. Still had plenty of valuable troubleshooting tips.

The magpul buis front sight is adjust the same as the the A2/M4
1. Start by making sure the sights are a match pair, belong together.
then go to post 11 in this link http://www.northeastshooters.com/vbulletin/threads/143705-Zeroing-in-an-AR-15-for-HP-competition . Forget about it being for "match rifle" principle is the same.
2. Get back to 25 yards if your going to shoot with support use a sand bag and support your forward arm not the rifle. A rifle restrest like the lead sled can be used to get you roughly dialed in. Your point of aim/ point of impact will change a bit when you remove the rifle from the rest.
Personally I would adjust the front sight post until it was flush with sight body.
take 3 shots at 25 yards and if your shots are not very close together say with in 2" you or rifle need some looking into. I believe the circle on the 25m military sight in target is 2"?

As stated above the buis at least the ones I have used MI and cheap ass UTG have surprised me. Where good enough for "hits " on target.
Meaning once they where set up I could hit a 18"x18" target consistantly out to about 300 yards....just not always in the middle.