Going below 1 MOA at 100yrds

Oldmauser

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I built an AR which is supposed to shoot well below 1 MOA at 100yrds.
223 20" 1:8 twist match barrel from a reputable manufacturer
hyperfire trigger
5-25 pst II Vortex scope
I tried off the bench 69 SMKs, 55gr fiocchi, 55 gr GGG and my average group is 3 MOA. I assume it's not the barrel, it's me. Where should I look first on my way to tighten those groups?
 

Badfinger

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Checkout some training videos on shooting the AR, they are more difficult to shoot tight groups with. With the 1:8 twist i would think it would shoot heavy bullets well. PRACTICE
 
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Rocketvapor

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Tell us more about your build.
Your 'off the bench' setup.
And
Your shooting history.

I'll admit that just a few years ago, after I turned 60 :),
The wife and I where knocking the black out of 6 inch splatter targets @ 100 yards with 2 pin AR builds.
Now we are a little better.
 
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Oldmauser

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I am using a front and a rear bag, no bipod. I am shooting off the table. With 25x magnification at 100yrds I am aiming always in the bullseye. I was sighting in the scope last time using 55gr GGG. I am shooting 5-shot series and using a sporting target I get 2 10s, 2 9s and an 8 (on aveage). The groups are way to wide. The barrel is capable of 3/4 MOA at 100 yrds.
 

The DFC

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Use a sled if you can-bolt it in and see what the rifle with as little shooter input as possible can do. Try other ammo-77gr mk262 type stuff. After you verify the rifle can shoot like it should-improve your shooting skills from there.
 

mheimer_45

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Are you using a free float handgaurd? Any muzzle devices? Did you true the receiver face? Are you using a $75 barrel? Throw the bag in trash and get a decent bipod (with all the adjustments). And get some decent ammo for fucks sake. Black hills or federal match. Don’t shoot for groups until 150 have been fired.
 

STI_1911_Guy

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I will bet you can shoot better than 3MOA off the bench, most anybody with even a little experience can shoot better than 3 MOA, There is something wrong with your setup.
 

Foxtrot2November

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I built an AR which is supposed to shoot well below 1 MOA at 100yrds.
223 20" 1:8 twist match barrel from a reputable manufacturer
hyperfire trigger
5-25 pst II Vortex scope
I tried off the bench 69 SMKs, 55gr fiocchi, 55 gr GGG and my average group is 3 MOA. I assume it's not the barrel, it's me. Where should I look first on my way to tighten those groups?
I think I need alittle more info on your build to get a good picture to help. but I can say try some 53gr v-max and see. I use those in both my 18" builds and can get 1/2" all day if I do my job @100yds
 
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Yondering

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It’s all in the barrel. If you didn’t spend $600+ on the barrel sub 1 inch is very rare.
Negative ghostrider.

OP: his first sentence is partly right though - bullets, barrel, and bedding are what matter most to accuracy. (That's a bolt gun saying but in an AR, "bedding" refers to how solidly the barrel is connected to the receiver.)

A rifle shooting 3+ MOA with a variety of different loads sounds to me like either the shooter, or something mechanically wrong - either the scope, scope mounting, or barrel connection to the receiver. If you were struggling with 1.5-2 moa I'd think maybe you got a bad barrel or hadn't found the right load.
 
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Yondering

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With 25x magnification at 100yrds I am aiming always in the bullseye.
This is the other possibility, following up my post above - the shooter.

I don't want to assume too much, not knowing you or how well you shoot. However, there's a lot more to it than just "aiming always in the bullseye". Aiming is just a small part of hitting the target. Your body position & alignment are important, as well as how you load the rifle and your trigger control when you break the shot. With an AR, those things are more critical (and maybe easier to do wrong) than some bolt actions, so making sure you've got the fundamentals right is important.

A couple things to suggest, if you're not already doing them:
- Position yourself directly behind the rifle, so that the recoil drives into your body structure solidly. You can tell if this is right when you fire by watching the crosshairs and if they jump up or off to one side. Good positioning will result in minimal crosshair movement.

- That first suggestion is also related to how you load the rifle. Press the stock straight back into your shoulder and lean into it slightly, but be careful not to put any side loading into it, especially at the grip. One trick that helps me sometimes is to hold the fingers of my trigger hand completely flat (rather than wrapped around the grip) so I can only pull straight back. Keep your thumb on the palm side instead of wrapped around the grip when doing that. Verify your loading of the rifle by getting in position and on target, then close your eyes and relax; when you open your eyes the rifle should still be on target.

- Third suggestion is just dry fire. A few dry fire rounds before shooting helps me if I'm trying for best precision, like for load development.

Like I said, maybe you're already doing this stuff, but if not, I hope that helps.
 

M8541Reaper

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Are you using a free float handgaurd? Any muzzle devices? Are you using a $75 barrel? Throw the bag in trash and get a decent bipod (with all the adjustments). And get some decent ammo for fucks sake. Black hills or federal match.
All of this except the “throw the bag in trash” as that’s not a factor. Any shooter who can put on Velcro shoes can shoot groups off a bag.

OP,
It sounds like your issues are a blend between your build and fundamentals on a gas gun. Trying to go sub minute with shit ammo is a waste of a range lane. Shit your rifle could be a laser but your parallax might be off. Do you have a cheek piece riser or are you holding your head up to get the proper sight package? Is there slip between the upper and lower? Are you torqued to spec on your scope mount? Do you know your torque specs and have a reliable torque wrench? Is your upper an LMT 1 piece monolithic or is it like every other AR upper where it is a 2 piece? If a 2-piece is your scope mount partially (or fully...you laugh but I’ve seen it) mounted on the handguard? Is the gas block too big for the handguard and touching? Is the handguard cheap and so long that it flexes and causes the barrel to touch when you lay the rifle on a support? is it a true free-float handguard?

There are literally too many factors that come into play when talking about an AR build not grouping. Or there might not be anything wrong with the rifle and your gas gun fundamentals need to be overhauled. A few have said that 3MOA is too big to just be a shooter issue...but I’ve seen some horrendous 556 groups at 100.

Tear it all apart, rebuild it, check and double check your fitment and torque specs, realize you should have just bought a used LMT MRP in the PX for $1,500 and spared yourself the wasted time/money/frustration, then grab some FGMM and see if that closes you up.

I hope it works out for ya man. It’s all a learning experience so don’t get too frustrated.
 

Oldmauser

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Thank you guys for your feedback. Referring to your questions:
1. yes, it's a free floating barrel.
2. it's a 20" HBAR Criterion Barrel.
3. yes, I have a muzzle brake (the Jerry Miculek DPMS)
4. As to attaching the barrel to the receiver- it was done by a gunsmith.
5. I have a Vortex Viper Extended Cantilever mount installed.
Thank you for the recommendation to sight it in using premium ammo. I am heading today to the range and will be shooting 77gr Hornady Black. My shooting experience- I am shooting comparable groups with my 16" stag arms using 1-6 bushnell.
 

bfoosh006

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Double check the scope mount screws., top to bottom

Double check the brake

Make sure your FF tube is tight.



You did clean the barrel prior to shooting for precision , right ?.... especially if it is nitrated. And most barrels need a break in period.
What specific Criterion barrel ?

As for always aiming for the bullseye... I tend to aim at the top of the bullseye dot, or put a black marker dot for a POA... most bullseyes are to big.
Or, if your crosshair intersect point cover your POA... aim at the top of the orange dot... I prefer NOT to shoot out my POA... so groups next to it are fine for precision testing.
You can just see the added black marker dot ... the orange paster is 1"IMG_2738_JPG-386184.jpg

Make sure your bags are aligned front to back ( and you ) so the AR will recoil in a consistent straight line

GGG , Fiocchi , 55gr ammo probably won't give you the best groups.

I would try some other ammo. Currently Aust. Outback 69gr SMK and 55gr Blitzking BOGO at Global Ordnance have proven to be accurate in many different AR's

And sometimes it is the nut on the end of the barrel.... ( Lol ) , no offense intended..

Because AR's got a lot of parts banging around every time you pull the trigger, so even shooting off the bench can be a learning curve.

Please keep us posted as to your results.
 

bfoosh006

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Oops.. I forgot to say... make sure your gas block is not even close to "bonking" your FF tube upon firing... from possible barrel whip.

If you aren't sure of what that contact distance is.. post a few photos of the gas block and FF tube.
 

cwmoss

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Get all of the paralax ( ? spelling) out of the scope, that could open your groups up a bunch.
 

TripleBull

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My son's DPMS AR-15 cost less than $600 for the whole gun and it's shot quite a few <.75 MOA 5 shot groups at 100.

However, his DPMS is very sensitive to the ammo/load. After you go through the advice above, if you haven't looked broadly at factory ammo or handloads, that approach is worthwhile.

My AR-10 is an Armalite TAC-20 with the only significant mod being a Wilson Combat 2-stage trigger. I have the same optic as you. On a good day, it will shot factory ammo (FGMM 168) at less than 0.5 MOA @ 100. More typical is .7 to 1.2 and I've only gotten <.5 when shooting from the prone.

How many rounds do you have down the tube? Have you looked at the leade and rifling with a bore scope?
 

Oldmauser

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I was shooting today at 50m (the 100m rang was unavailable). The rifle is sighted in at 100m, I did not play with the turrets, just trying to get the tightes group possible. The target is measured in cm- the 10 ring (the white one) is exactly 0,5 cm (0,2 in) wide.
I was shooting 77gr Hornady Black using Leapers bipod.
 

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d2wing

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One thing often overlooked is the bolt and carrier. I had a similar problem with a PSA build. Turns out the the bolt was binding in the bolt carrier. Changed out to BCM bolt group and problem solved. Improper bolt closing can be a serious issue as can a light buffer.
 

Gatorshark

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Maybe go back to assembly and make sure barrel nut is torqued. Scope mount torque, rings torqued, etc.
 

Yondering

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Agreed, a Craddock chambered Bartlein is like $550 or less depending on what you are looking for.
Heck, I'd bet a large number of us here have had sub-1 moa results from barrels costing half that much.

I just spun up a couple BHW barrel blanks over the past couple months that cost me well under $100 each, and both are capable of sub 1 moa groups. Granted most guys are making their own barrels, but as long as you avoid bottom of the barrel stuff like Bear Creek, it's not that hard to get an AR to shoot well with the right ammo and a reasonably decent barrel.
 

Foxtrot2November

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Heck, I'd bet a large number of us here have had sub-1 moa results from barrels costing half that much.

I just spun up a couple BHW barrel blanks over the past couple months that cost me well under $100 each, and both are capable of sub 1 moa groups. Granted most guys are making their own barrels, but as long as you avoid bottom of the barrel stuff like Bear Creek, it's not that hard to get an AR to shoot well with the right ammo and a reasonably decent barrel.
I agree. I have a BCM mk12, WOA SPR, & Criterion 16" hybrid barrel CL and all of them are sub-moa all day. and they are $300 and lower
 

x_789

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$600 barrel is laughable. I have a PSA that is sub moa with 60-62 gr hand loads. It's a 1/7 and won't shoot heavies. I tried 69s and 77s just won't go below 1.5-2 moa.

My son built his first AR and took it out yesterday. It's a WOA spr and was sub moa with my bulk 60 gr vmax off my Dillon and was .75 with 69gr smks right out of the gate.

Cheap ammo was 3in groups. If you don't have good ammo no gun is going to fix that.
 

acudaowner

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my favorite part of learning is that it never ends just when I think I understand what i am doing I find there is more to it and i have to start over .
 
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Dolomite_Supafly

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I love Hiperfire triggers but I have had a few people say their guns had accuracy issues when they used them. I recently replaced mine with a NM two stage. I will see if it makes a difference during the next range trip.

I have a BA that did not shoot as well as I had hoped. I also have a BHW that is still settling in that should shoot better.
 

Dthomas3523

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If he’s having any doubt that “it’s probably me” most anything else is moot.

If you’re not entirely sure that your fundamentals are NOT the factor in a gas gun, you cannot even begin to diagnose a problem.

Lock time and multiple recoil impulses in a gas gun exploit poor fundamentals much more than a bolt gun.

Find someone who you 100% trust to drive it properly and go from there. Otherwise you’re just chasing your tail.
 
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davsco

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yep get someone else to shoot it and see how he does. find someone at the range that is printing nice groups.

when you dry fire from that same shooting position, are the crosshairs staying on target after the 'shot?' they should be.

double check scope/mount/etc. even swap out a diff scope if you or a buddy has one.

is there any movement in the gun when you are getting ready to fire? if you have it properly supported front and rear, there should pretty much be zero movement.

make sure your fore end is resting on the front bag, NOT the barrel.
 

Oldmauser

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There is zero movement while I shoot. I checked the mount and the scope- it's properly torqued.
I cannot easily check however the barrel nut- it's unde the handguard. What could be the problem with that? Should I take it to the gunsmith to re-check?
 

davsco

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before you take it back to the gunsmith, have a few buddies, who have demonstrated they are accurate, shoot it and see how it does with them. unless the 'smith just forgot to tighten the barrel nut, that shouldn't be the problem.

what were the 69g smk's you shot, what brand? if they were a premium brand (federal, black hills, etc) they def should be moa or better out of a decent gun.
 

davsco

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yeah try federal gold medal and/or hornady match and/or black hills 69 or 75g match. but, you should be getting better than 3moa with what you're using. where do you live, maybe someone here is nearby and can help you problem shoot this.
 

Precision Underground

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I built an AR which is supposed to shoot well below 1 MOA at 100yrds.
223 20" 1:8 twist match barrel from a reputable manufacturer
hyperfire trigger
5-25 pst II Vortex scope
I tried off the bench 69 SMKs, 55gr fiocchi, 55 gr GGG and my average group is 3 MOA. I assume it's not the barrel, it's me. Where should I look first on my way to tighten those groups?
How confident are you that the highlighted statement is not the problem? At 3moa my guess is that it is not your shooting and something is loose or something is touching something that it shouldn't. Are the groups horizontal, vertical, or random?
 
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rsbhunter

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Didn't read all the posts, so if it was done, forgive me. Did you true the face of the receiver to make sure the barrel extension has 100% contact with the receiver?....I now do this to every build....cheap insurance.....rsbhunter
 

x_789

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I was shooting today at 50m (the 100m rang was unavailable). The rifle is sighted in at 100m, I did not play with the turrets, just trying to get the tightes group possible. The target is measured in cm- the 10 ring (the white one) is exactly 0,5 cm (0,2 in) wide.
I was shooting 77gr Hornady Black using Leapers bipod.
How are you measuring your groups? That target is only 5cm across that is just under 2 inches. So if your groups are all on that target at 100m your under 2 moa at 100 yards. Still not great Hornady black is not a match ammo by any means. Still in my experience its much better than most cheap stuff like WWB and AE. It is probably a 2MOA ammo in a good rifle. What your showing there looks pretty good with that ammo. Is it 62gr ammo? I have found lots of rifles like 60-62gr better than 55s.

Are you using some type of rear bag or rest? Its can be very tough to get a colapsible stock steady since there isn't much realestate on the bottom of them.