Home Forums Hunting & Shooting AR and Tactical Rifles 224 Valkyrie issues

That's why I'm thinking either a chamber defect (roughness, pitting, or radial grooves/scratches) or partial extraction and re-insertion while the case is still expanding.

So, you're saying it's endemic to the case design?

A couple things come to mind after reading this discussion. Radian stopped offering the 224 Valkyrie- possibly because of these issues? Also, the more I think on this- the brass won't extract with gas when fired and won't extract manually until a short time after firing- 10-30 seconds after once it has cooled, then it will usually manually extract with the charging handle. That seems to indicate a chamber geometry issue IMO, which may or may not clean up with a chamber polishing but if it is so severe, it may take more than a polishing.

I'll still try the small base dies to start with, then go with more aggressive methods as I move forward to see which one has the desired effect. It is interesting to see I'm not the only one who has had this problem and my son has found several articles/forums that have reported this problem with the Valkyrie... I'll let you know how things progress

Nope, I always try really hard to make my semi-autos function in that mode..............don't want any single shot AR's.

Really hard to say w/o being there & & handling the gun. i think a 20" barrel is a bit better with a +1" rifle gas system, but it SHOULD fuction as is, all things being equal & correct.

As to the HS as a possible issue; if it's very short, it's unlikely that a Go-Gauge would close...............I've had that happen exactly once on 25-30, 5.56 barrels.

Could be a throat neck issue though......................never had exactly this same issue on an AR so really hard to know, absent the gun in hand, but 2 of them at the same time is highly suspicious.

MM

I had an idea of how to polish the chamber but I'm curious what you guys use for this chore and how to go about it without damaging the chamber?

0000 steel wool wrapped around a bore brush. Maybe some Remington 40X bore cleaner or Kroil mixed with JB polish paste slathered on the steel wool. Short section of pistol cleaning rod in a drill and some sort of collar over the rod so as to keep it from hitting anything unwanted.

I've been shooting a 6.8mm Rem SPC (parent case for the .224 Valkyrie) for several years now.
I shoot 90% reloads and have no extraction problems.
I also use SB dies.

Sounds like a gas issue, or insufficient gas to reliably cycle the cartridge out of the chamber when firing. I'd double check gas block alignment. Next thing to check is hole diameter in the barrel. If it's too small or there is any other type of restriction, that may be the problem. I'd run a regular gas block. Leave the AGB with someone else, if that is what you are trying to use. There's really no reason to run an AGB unless you are shooting suppressed.

OP, please post whenever you get a resolution to this problem.

If polishing the chamber & checking the size of the gas port (should probably be somewhere between about .093-.103"), then I'm going to bet that you have a chamber that may be on the small size, thus not allowing the round to be extracted until the brass shrinks as it's cooled enough to be removed.

The minimum taper case in a tight chamber combination could be the root cause, taken together, not allowing the brass to change size fast enough because of reduced clearance in the cold condition.

Don't know anything about Radian barrels so can't comment on that item..........the rest of their stuff is nice, but also expensive.

When that round 1st came out, as I recall, there were some problems with barrels from various suppliers, especially regarding accuracy.

Paul Craddock at Craddock Precision, was one of the guys who figured out the chamber & the gas port size pretty early on & as far as I know, his barrels have all been good.

If you can't resolve the problem with chamber polishing & verifying the gas port, if it was me, I'd be telling Radian that you have 2 barrels with the exact same issue & send them back & order new one from Craddock.

I giving you the benefit of the doubt & assuming that all the rest of your build & gas systems are OK.

MM

I may have to check with the neighbor who is a retired machinist to see if he has a set of pin gauges so I can check the gas port and the chamber diameter. Checked the brass with a mic and there is just shy of .010" taper in the case, so you're right on that issue and I can see where a chamber even slightly out of spec could cause a real problem

We have built several .223s with the same parts minus the barrels and have had good luck with all the components so far- to include excellent accuracy.

SB dies are due in on Thursday so I'll throw some loads together quickly, polish the chamber, and check the gas port and run to the range on Friday if I can squeeze it in and see how my results are. I'll post results after the range trip and actions to take after...

Since you've been using virgin brass I doubt that SB dies are going to fix the problem.

If the brass base diameter is the problem, usually brass won't chamber easily.

You can measure the gas port close enough to know if you have a problem with a set of calipers very carefully with fine tips on the ID side.

MM

Is there an easy way to check headspace without Go/No Go gauges? I hate to invest in these gauges I may never use again for this, but it may be necessary in this case....

I sincerely do not believe it's a headspace issue. An AR will crush a 223 at least 3 thou if it has to. That is something that won't chamber slowly, by hand without resorting to the FA.

You'd be better served getting a Hornady headspace tool and checking the difference between unfired and fired case headspace measurements.

Well, hopefully we're getting it narrowed down....

Do they jam every time or just sometimes? How is ejection when they function?

Every fired case is stuck in the chamber until it cools, then it extracts manually with some effort. Extraction and ejection after that and with unfired rounds is perfect otherwise. My thought at the moment is chamber issues of some sort. My son watched while I fired his rifle and the bolt tried to pull back but couldn't move more than a little bit when firing.

What Tyrone said about headspace; almost positively not a HS issue.

If the bolt is attempting to move, besides what all I've already said about straight cases & chamber dimensions, if your gun had enough gas & with a sticky case, seems likely to me that you would be ripping some cases rims off............but you haven't reported that.

So as I suggested earlier, get a dimension check on the gas port in the barrel as a 1st to do.

Shouldn't take more than a few minutes to disassemble, check & polish the chamber.

I would not do anything more until you do that as you are chasing your tail. Eliminate one variable at a time.

MM

That's why I believe the BCG is moving partially back and then moving forward, jamming the partially extracted case back into the chamber. We are on the same page.

I had this problem with a 6Arc, McGowan barrel.
I had to split the recievers and tap the case out with a cleaning rod.

Fired a handful of rounds thinking it might improve. Cases were not frosty and chamber looked smooth.

Considered polishing the chamber and decided to call McGowan, ultimately sent it back and they took care of it.

Sounds like you have tight chamber, which is good. It might improve as at least yours will eject when it cools, mine would not.

Good luck

They make chamber hones specifically for this.


Edit, not seeing one for a valkyrie, doesn't mean they are not out there.

https://www.brushresearch.com/brushes.php?c2=183

Maybe a 6.8mm will work?