could use some help debugging an AR

[stinkyDrunk]

I bought this rifle sort of on a whim last summer, had some extra cash in my pocket from a side job and have always wanted to have an AR with a WOA barrel.

Didn't get around to working up a load for it until earlier this year. These are the best groups I got out of it using 77 SMKs over Varget (300 yard groups, targets are printed on 11" x 17" paper).

Not great, nothing sub moa. I expected better. On a recent range trip I found myself re-zeroing the rifle...and getting a little frustrated. So for the 4th of July I took her to the range again, along with an AR I call the NoVLTOR (Noveske barrel in a VLTOR VIS upper receiver). The NoVLTOR is a solid shooter with the right ammo. The test I did yesterday was to shoot 5 rounds from the bench with each rifle, then 5 rounds from prone off the bipod. Ammo was a generic varmint round I have that's not been tuned for either rifle. The same lower was used for all shooting.

Notice how the WOA rifle's groups on the left shifted up about 1" or so, while the NoVLTOR stayed fairly consistent.

I also tested the optics by swapping them between the 2 rifles; this test was inconclusive, and after realizing this it was close to 100 on the range and I was sweating my balls off so I called it a day.

The WOA rifle's upper components are:

WOA 1/7 20" barrel
Daniel Defense rail
no name upper receiver and BCG
NF optic in Bobro mount

I'm thinking about replacing the upper receiver. Maybe there is some weakness there, and stiffening it up will get this rifle shooting better.

Thoughts/recommendations appreciated.

 

[jeff1383]

Re: could use some help debugging an AR

Is the twist rate and barrel length the same on the Noveske? I know in my exp with loading SMKs in my grendel that seating depth was CRUCIAL in getting them to group tight. Id say stick with the 23.7 and play with your seating depth IMO.

 

[stinkyDrunk]

Re: could use some help debugging an AR

They are both 1/7 but the Noveske barrel is 16" while the WOA is 20".

ETA: and I loaded the 77s to mag length as a single-shot AR doesn't make sense for my purposes.

 

[jason8251]

Re: could use some help debugging an AR

I had a 20" Noveske in a VIS and it grouped 77gr SMK's over 24 gr Varget @ 2.250" really well. I know this probably doesn't help much but it's worth a shot.

If you have the means you could put the WOA barrel and BCG in the VIS and see what happens (see if the shitty groups follow the barrel)

 

[stinkyDrunk]

Re: could use some help debugging an AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jason8251</div><div class="ubbcode-body">
If you have the means you could put the WOA barrel and BCG in the VIS and see what happens (see if the shitty groups follow the barrel) </div></div>

Ugh. Ya, I see your point. Not crazy about the idea yet though.

 

[K_4c]

Re: could use some help debugging an AR

Have another well versed shooter pull the trigger and see if the trend follows... I'm not saying your a bad shot, just consider all the mechanical variables (shooting fundamentals are key with semi's) there are before swapping uppers.

Just b/c both barrels are a1:7 twist does not make them equal (as you already know...) I believe Noveske's use a 3 groove barrel correct? I'm not sure how WOA spins their barrels, but no two guns are alike.


Another idea maybe the no name upper may not be be in spec (as in the picatinny rail maybe slightly different from your Vltor upper).

 

[CTown137]

Re: could use some help debugging an AR

One thing you may want to consider is your bolt. I know having a matched bolt will increase accuracy. My Noveske barrel came with a matched bolt (your's may have too), then the no name one you have now may not be matching up great with your WOA barrel.

 

[geraldsd]

Re: could use some help debugging an AR

I found that my AR seems to prefer ball powders. H335 in particular. I have a bolt gun in 5.56 and it really likes Varget and 4064. The groups are decidedly different between the two different powders and rifles.

 

[McLarenross]

Re: could use some help debugging an AR

Seems simple but did you tighten the barrel nut properly on the WOA? Snug but not tight will cause issues like the shift you saw and poor accuracy. Yes if you are using the same bolt between both barrels you need to verify head spacing for it to both barrels.

 

[stinkyDrunk]

Re: could use some help debugging an AR

Both upper receivers were purchased complete.

Good ideas gentlemen, keep em coming. Thanks.

 

[Russ D]

Re: could use some help debugging an AR

Strip the WOA upper and rebuild it. Only way to eliminate variables. You need to make sure things like the gas block, and barrel nut are sufficiently torqued. Then strip the barrel with a good copper solvent like Wipeout and get it nice and clean. Then take off you muzzle device and leave it off for testing purposes. My WOA 1/7 shoots Hornady 75 HBTS to sub moa with 24.5 grains of Varget loaded to 2.260. They fit in the mag. Varget in 223 doesn't like space in the case so all of my Varget loads are hot. After your upper is rebuilt properly then you can get down to deciding if you have a bad barrel. As for the bolt as long as it passes a Head Space test then that isn't really part of you issue. That barrel should shoot much better than it does. As for the no name upper I honestly doubt that it is part of your issue. Perhaps the top rail could be out of spec but that wouldn't cause your issue.

 

[Russ D]

Re: could use some help debugging an AR

The rail isn't touching the front sight post is it?

 

[RobertM]

Re: could use some help debugging an AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Russ D</div><div class="ubbcode-body">The rail isn't touching the front sight post is it? </div></div>I knew better but admit you had me popping open the safe regardless........

 

[Sterling Shooter]

Re: could use some help debugging an AR

OP,

Your bench shooting shows good elevation and poor trigger control. If not trigger control, look for movement of the right elbow, position too high, high right shoulder, varying head pressure, and changing eyeball/eyepiece relationship.

 

[Russ D]

Re: could use some help debugging an AR

Have you tried different bullets yet? I wouldn't try to fit the gun to the bullet.

 

[Longstaff]

Re: could use some help debugging an AR

The barrel is designed to shoot 77smk's, so there's definately a problem. IIRC, these have a wylde chamber so there a littler longer leade.

I'm sure you've checked most of these, just throwing stuff out.
I would check the gas key first.
Make sure FF rail is tight.
Make sure barrel is properly torqued.
Unscrew the flash suppressor, check the crown and see how it shoots without it.

If the toprail is out of spec, the scope mount might not be engaging properly. Maybe try some fixed rings?

 

[Russ D]

Re: could use some help debugging an AR

I have the same barrel and mine shoots the Hornady 75 HPBT's better.

 

[Sterling Shooter]

Re: could use some help debugging an AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Longstaff</div><div class="ubbcode-body">The barrel is designed to shoot 77smk's, so there's definately a problem. IIRC, these have a wylde chamber so there a littler longer leade.

I'm sure you've checked most of these, just throwing stuff out.
I would check the gas key first.
Make sure FF rail is tight.
Make sure barrel is properly torqued.
Unscrew the flash suppressor, check the crown and see how it shoots without it.

If the toprail is out of spec, the scope mount might not be engaging properly. Maybe try some fixed rings?</div></div>

A word about shooter/target analysis: we begin with an assumption that the rifle and ammunition are satisfactory. This means trouble-shooting will initially be about shooter consistency and compensation for the effects on trajectory. There could be a multitude of errors, yet when the shooter concentrates on position, principles, and effects on trajectory, errors can be quickly eliminated. It is only when errors are not resolved that the rifle is considered as possibly being broken or that the ammunition might be defective.

So far, we have folks here which it appears have put the cart before the horse, looking for fault with the rifle and ammunition before looking at obvious shooter errors.

No doubt the shooter could have a broken rifle or defective ammunition, but, don't overlook shooter error, and remember, since the bullet always goes in the direction the barrel is pointed most errors will indeed be all about the shooter being inconsistent.

 

[mckenney810]

Re: could use some help debugging an AR

I might sound like an idiot but are your scope mounts real tight? i was shooting A firearm and the scope mounts kept getting loose. after really torching them down it shot fine. btw i love your rifle that is a sweet scope. you did have 1 nice group from prone. i would try a lead sled or some other really nice rest because those groups are close maybe just because your shooting it off a bipod and your moving your shoulder without knowing.

 

[jink122]

Re: could use some help debugging an AR

did u text the noveske on the same lower?

 

[Russ D]

Re: could use some help debugging an AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sterling Shooter</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Longstaff</div><div class="ubbcode-body">The barrel is designed to shoot 77smk's, so there's definately a problem. IIRC, these have a wylde chamber so there a littler longer leade.

I'm sure you've checked most of these, just throwing stuff out.
I would check the gas key first.
Make sure FF rail is tight.
Make sure barrel is properly torqued.
Unscrew the flash suppressor, check the crown and see how it shoots without it.

If the toprail is out of spec, the scope mount might not be engaging properly. Maybe try some fixed rings?</div></div>

A word about shooter/target analysis: we begin with an assumption that the rifle and ammunition are satisfactory. This means trouble-shooting will initially be about shooter consistency and compensation for the effects on trajectory. There could be a multitude of errors, yet when the shooter concentrates on position, principles, and effects on trajectory, errors can be quickly eliminated. It is only when errors are not resolved that the rifle is considered as possibly being broken or that the ammunition might be defective.

So far, we have folks here which it appears have put the cart before the horse, looking for fault with the rifle and ammunition before looking at obvious shooter errors.

No doubt the shooter could have a broken rifle or defective ammunition, but, don't overlook shooter error, and remember, since the bullet always goes in the direction the barrel is pointed most errors will indeed be all about the shooter being inconsistent. </div></div>

No doubt, but he specifically asked to help debugging the rifle and not himself.

 

[stinkyDrunk]

Re: could use some help debugging an AR

Took the WOA rifle to the range last weekend. Had another shooter drive the gun, his groups were larger than mine. Also tried a few other flavors of ammunition, including MK262 and some of that Hornady Zombie stuff. Best group of the day was with the Zombie ammo (5 shots about 1.25").

After shooting, I stopped and spoke with the gentleman who built the WOA upper. Learned a bit more about the parts that went into it - LMT BCG, Stag upper receiver. He built himself an identical setup at the time he built the one I have. I showed him the groups that were shot, and he agreed they <span style="font-style: italic">should</span> be smaller. We're going to make a trip to the range and shoot our rifles side by side.

In response to some questions/suggestions, nothing is loose on the rifle at all. Rail is not touching FSB.

Again, thanks for the feedback.

 

[Sterling Shooter]

Re: could use some help debugging an AR

Yes, and would not omission of any arena where errors are likely undermine the OP's discovery? Thing is, some replying to the OP are, it appears from their statements, nimrods on the subject of shooter/target analysis. They are not likely to be able to properly appraise their own shot misplacement, much less that of another novice shooter. The fact is unless the gun is broken, the ammunition defective, or the sights loose, all bullet misplacement can be isolated to the shooter's inconsistent position (control), changing perspective of aim, trigger control, or not correctly countering for the effects on trajectory. Again, no doubt, the OP could have defective equipment, but today, unless the rifle was built by a moron, the shooter should first look to what he's doing that's inconsistent.

 

[sinister]

Re: could use some help debugging an AR

Do both rifles have the same trigger? I see you've fired the NoVltor upper on the WOA lower -- what were the results on the other lower?

Did the same gunsmith build both rifles?

I can't tell but it looks like your A2 flash suppressor was installed with a crush washer (vice a peel washer, shims, or A1 spring washer) -- this can cause torque and stretching at your muzzle, literally making the muzzle "Trumpet" slightly and enlarging your groups.

What kind of dies did you use to seat the 77s? Generic light/flat-base varmint bullets should group tighter than 77s at 100. There are better bullets than 77s for accuracy -- have you tried 69s or another known good factory match (not the 262s) cartridge?

Still a bunch of variables questions you have to clear up.