Help with 224 Valkyrie AR accuracy issues

[Serpico1985]

Hey guys,

Wondering if anyone has any ideas about this situation. Buddy of mine wanted a 224 Valkyrie AR. He doesn't usually like AR's, he's more a a bolt gun guy. Anyway, I tried to talk him into getting a factory 224 AR but he wanted me to put one together for him. I've built 7 AR's previously, never had any issues. Here are the specs/parts.

-Bartlein 22" +2" gas system medium heavy barrel (.875 at the muzzle), straight flutes, threaded with thread protector from Craddock Precision.
-Vltor MUR upper
-Aero Precision BCG
-Mil-spec lower
-Geissele MK4 15" rail
-Geissele SSA-E trigger
-A5 Receiver extension
-Magpul PRS Gen 3
-Colt and Geissele other various small parts
-Vortex PST Gen 2 FFP 5-25x50, in a vortex scope mount

I recently re-barreled my precision AR with a JP 224 Valkyrie 22" barrel, same +2 gas system. Mine has a JP bolt in a Noveske carrier.

Prior to us going to the range he installed the Area 419 Hellfire system on this new 224.

We went to the range and shot both for the rifles side by side. We shot factory FGGM 90gr SMK ammo. Mine shot pretty good grouping well under 1" at 100 yards. My buddies rifle on the other hand wasn't grouping at all. I don't have pictures of the groups but they were all well over 1". Like 1.5"-2" with that same ammo. We shot it both with the muzzle brake on and off (area 419 adapter still on of course).

Then my buddy went back to the range a week later with another friend and shot the same factory FGGM 90gr SMK ammo AND factory federal 80.5gr bergers and it still did not group well.

Now for some questions that maybe y'all could help us out with:

-We need to remove the area 419 hellfire system from the rifle and shoot it with just the thread protector as a base line correct? Is it possible that if the area 419 adapter was screwed on too tight or too loose to affect accuracy this much?

-With this Craddock Bartlein barrel I have only heard great things. What should one expect accuracy wise with this set up?

-Is the brand of bolt an issue?

-What other ideas/things to check do you have that could fix the group size? We're open to all suggestions.

Thank you for your time and thoughts.

Zack

 

[Near miss]

You could start from harmonics.

 

[Halfnutz]

Check/switch scopes.
Switch shooters.

 

[The King]

I have been through this. With my LWRC.

My recommendations.

1. What twist is the barrel?
2. Fire 50 rounds of shit ammo (75 TMJ) and clean it thoroughly. Have had several barrels need this treatment of late.
3. Turn down the gas.
4. Check to make sure you have good gas block clearance.
5. Check headspace.
6. Try different muzzle devices.
7. Send to Craddock with a bunch of ammo.

Do you have group pics?

A great barrel maker turns out 1/50 barrels that don’t shoot. Factory is probably 1/5.

Nobody never turns out a barrel that doesn’t shoot IMHO.

 

[Serpico1985]

-7 twist barrel.
-Non-adjustable gas block, gas block does not touch the rail.

We will remove the muzzle device and shoot some groups with just the thread protector on. If that doesn't improve things we'll swap my scope onto his rifle and repeat. If that doesn't help I'll let you know.

 

[The King]

-7 twist barrel.
-Non-adjustable gas block, gas block does not touch the rail.

We will remove the muzzle device and shoot some groups with just the thread protector on. If that doesn't improve things we'll swap my scope onto his rifle and repeat. If that doesn't help I'll let you know.

Does it shoot one round as a flyer in a 3 shot group and the other two touching??

 

[Serpico1985]

So far it’s been a shotgun pattern. It’s not grouping well then throwing a flyer.

 

[The King]

So far it’s been a shotgun pattern. It’s not grouping well then throwing a flyer.

I bet its the optic - that said...

There is one more strange one to check out. Make sure you don't have the bolt for the 6.5 Grendel. Aero makes both of them, and they look very similar. Measure with calipers against your JP.

 

[Serpico1985]

Thanks for the tip King. I will. Let y'all know something once we make it back to the range.

 

[bfoosh006]

Start with the easy stuff... make sure everything is snug / tight.

Try shooting it off a stable bag... I shoot better from a bag then a bipod.

I would try it without the 419.

Try different ammo... at least for the time being. His barrel might not like the 90gr. Is this the "new" version of the 90gr SMK, with the thicker jacket ?

 

[kyzim311]

What is the twist rate of the barrel in your rifle? You said your friends barrel is a 1:7, bit what is yours? The 90 smk can be marginal with 1:7 twist guns

 

[jLorenzo]

How well does your friend shoot other guns?

 

[max1840]

I had issues with my .224V AR build but found that the less than acceptable accuracy was do to my less than acceptable AR fundamentals. You will see that stated all over the Hide. I worked hard on that issue and now really enjoy shooting the Valkyrie in the AR and find that when I do my part the rifle shoots under an inch at a minimum. No other changes to the rifle. Sight picture, breath control, trigger pull and the most important to me follow through.

 

[S800]

I had a similar issue with my LMT MRP in 224v.. discovered that the 88gr and 90gr bullets were getting distorted while feeding from some 6.8 mags. I even found a couple of plastic tips from the 88gr broken off in the upper. 75 grain fmj ran fine. Hope this helps!

 

[lash]

I put together a very similar build to that one.
VLTOR MUR Upper
Premium lower
22” Rock Creek 6.7:1 +2 barrel by Craddock
Matched bolt from Craddock
Seekins handguard
Adjustable gas block
Geissele SSA-E
MagpuGen 2

My experience was and has been positive, which I attribute to a couple things. The adj gas block has allowed me to tune for the 90s and then also the 88s and 75s. An adjustment is required when I went from the factory 90s to factory 88s. The 88s wouldn’t even cycle the bolt all of the way until I adjusted the gas.

The matching bolt. Not normally a big deal, but I appreciate mine. At least check and measure to be sure that you have a good bolt to extension fit.

That all aside, I just recently saw where someone was having similar accuracy issues and discovered that the left side of the feed ramp was scarring bullets upon loading. After the feed ramps were polished, accuracy was there.

 

[502Chevelle]

Make sure some dumb ass didn’t screw a sling stud up into the bottom of the gas block and cause clearance problems. Oh wait, that was me....never mind.

 

[Serpico1985]

Out of curiosity what would you estimate the round count to be on this barrel judging by the gas port erosion? I’d like to limit responses to people familiar with gas port errosion if possible.

Thank you

224 barrel:

 

[TimK]

I feel your pain. I built one with almost exactly the same barrel (mine is a 24") from Craddock. My problems were different from yours, but just as frustrating. I've resigned myself to shooting this barrel out in local matches and then switching to 6 ARC.

If the suggestions above don't fix it, you could try gluing the barrel in. Paul Craddock suggested that option to me in the midst of my mess. I did so but haven't determined for 100% certain if it helped. Pretty sure it did. He also mentioned something cryptic about changing the gas block to a fixed version. Neither of us could come up with a mechanism that would explain why it should matter, but he said he'd seen several instances where that change helped. I did that at the same time I glued in the barrel, and it does seem better. Unfortunately, I can't pinpoint whether it was one or the other or both changes that made the difference.

 

[Serpico1985]

I wondered if there was any chance that the barrel they sent my buddy was used based on the amount of gas port erosion. I'm not suggesting they intended to do that. But if the erosion was excessive for the current round count (210 rounds total of factory ammo) I thought it may be a possibility. Not to mention the fact that my buddy ordered a heavy barrel and they sent him a medium heavy. I don't know what normal gas port erosion is for a Bartlein barrel like this with this round count which is why I was asking.

I contacted Bartlein and they recommended the same thing regarding "bedding" the barrel extension as well as torqueing the barrel nut to 70+ foot pounds. I don't know if barrel nut torque would apply to this build since I'm not using the same rail system they use and Geissele recommends 40 foot pounds.

Thanks again for the info, I appreciate it.

Zack

 

[AZgeek]

Try the Berger 80.5 Fullbore bullet. If your gun doesn't shoot them well, you have serious problems.

 

[Dino11]

I have a new ARC barrel that I just put into service and the round count is at 200, my port erosion looks to be almost identical to the one you pictured. I did not capture a picture when I scoped it. They usually erode a little fast at first then tapper off after the sharp edges and burrs melt away.

Edit: to add photo of barrel

 

[Diamon4u1]

Hey guys,

Wondering if anyone has any ideas about this situation. Buddy of mine wanted a 224 Valkyrie AR. He doesn't usually like AR's, he's more a a bolt gun guy. Anyway, I tried to talk him into getting a factory 224 AR but he wanted me to put one together for him. I've built 7 AR's previously, never had any issues. Here are the specs/parts.

-Bartlein 22" +2" gas system medium heavy barrel (.875 at the muzzle), straight flutes, threaded with thread protector from Craddock Precision.
-Vltor MUR upper
-Aero Precision BCG
-Mil-spec lower
-Geissele MK4 15" rail
-Geissele SSA-E trigger
-A5 Receiver extension
-Magpul PRS Gen 3
-Colt and Geissele other various small parts
-Vortex PST Gen 2 FFP 5-25x50, in a vortex scope mount

View attachment 7565654

I recently re-barreled my precision AR with a JP 224 Valkyrie 22" barrel, same +2 gas system. Mine has a JP bolt in a Noveske carrier.

Prior to us going to the range he installed the Area 419 Hellfire system on this new 224.

We went to the range and shot both for the rifles side by side. We shot factory FGGM 90gr SMK ammo. Mine shot pretty good grouping well under 1" at 100 yards. My buddies rifle on the other hand wasn't grouping at all. I don't have pictures of the groups but they were all well over 1". Like 1.5"-2" with that same ammo. We shot it both with the muzzle brake on and off (area 419 adapter still on of course).

Then my buddy went back to the range a week later with another friend and shot the same factory FGGM 90gr SMK ammo AND factory federal 80.5gr bergers and it still did not group well.

Now for some questions that maybe y'all could help us out with:

-We need to remove the area 419 hellfire system from the rifle and shoot it with just the thread protector as a base line correct? Is it possible that if the area 419 adapter was screwed on too tight or too loose to affect accuracy this much?

-With this Craddock Bartlein barrel I have only heard great things. What should one expect accuracy wise with this set up?

-Is the brand of bolt an issue?

-What other ideas/things to check do you have that could fix the group size? We're open to all suggestions.

Thank you for your time and thoughts.

Zack

I am having similar problems with a 224 build. I sent the first barrel back and they gladly replaced it. The problem as I see it: the gas port. I didn’t scope the first one until after load dev was a disaster. There was a chunk hanging proudly into the bore. No amount of brushing or abrasives would cure it. Still showed with shiny copper on it. The 90’s were by far the worst. 88’s right around 1 MOA with Varget, but a modest load 23.6 grains. The new barrel has 100 rounds and developing the same chunk hanging in the bore. How did your project progress. ????

 

[Diamon4u1]

I have a new ARC barrel that I just put into service and the round count is at 200, my port erosion looks to be almost identical to the one you pictured. I did not capture a picture when I scoped it. They usually erode a little fast at first then tapper off after the sharp edges and burrs melt away.

Edit: to add photo of barrelView attachment 7619767

BTW, have tried 2000MR H4350 Varget all same results I would judge as poor. 24” heavy contour

 

[n2ishun]

Just at a casual glance...
That scope mount, it looks pretty unstable to me.
It shouldn't be too hard to try another....is it ?
Maybe it's just me, but I certainly would never choose one as unsupported looking as that.

 

[Defender63]

The factory Federal 90g. Fusion was a disappointment in my 224 Valk. With the flyers creating poor repeatability. Loading with CFE 223 and Barnes 78g. TSX bullets was much better but not as good as expected from the 22" 6 1/2 twist Bison barrel. Talking with the guy that is building my 6mm AR Turbo project he says not to expect much better because of the amount of freebore in the clambering of the way that barrel manufacturing specs are machining. He said he could make a barrel that he guarantees me 1/2 moa if I want the results that I expected.

 

[Rider47]

Last response from the OP was May 2021.
Was the issue identified and solved?