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

Measured the port and it seems to be around .101 or so without resorting to pin gauges... I'm out of steel wool at the moment so a run to the store for a couple other things and the steel wool also...

Now swap out your carrier with a known good.

I don't have a second 224/6.8 carrier laying around to try....

If this is a problem that developed over time, it's likely that something started to leak. IME, that is usually the gas key.

If you don't have another BCG, take the one you have apart, clean the gas key mating surface, use sealant on the mating area, and tie it down with new screws. Throw some new rings on the bolt while you are at it.

Gas keys themselves don't have to be replaced very often, unless their alignment with the gas tube was really horrible. I usually only replace gas tubes with every other barreling unless, again, their alignment was horrible. But you'll be able to tell by looking at either if they have excessive wear on them.

As I understood from his OP, he has 2 of these same barrels on newly built guns that malfunction exactly the same.

MM

Yup, two brand new guns just finished. First time shooting both of them. We built a couple 223s last year and they function flawlessly and are extremely accurate.

Polished the chamber a bit today, but I may give it another shot tomorrow to be sure I got it well enough. Soaked the steel wool with Iosso bore cleaner and some gun oil and ran the drill for about 2 minutes in the chamber with moderate pressure. It polished it up quite a bit and I'm hesitant to put a mirror finish on it, but that may be what is needed in this case.

My small base dies got delayed and come in tomorrow so I'll load up some ammo with the small base dies and the standard dies just for kicks and giggles to see if there is any difference. Needed another set of dies anyway for my son to start reloading.

Oil/grease your ammo. If the slippery stuff ejects, your chamber needs work.

Steel wool will take two lifetimes to get anywhere.

Yup, I realize that, but I'm taking it slow and easy to determine the issue and then go from there. My thought is to wrap some 2000/3000 grit wet/dry automotive sand paper soaked in oil around my brush and try running that for a bit to move a tiny amount of metal in the chamber. At this point I've got very little to lose and everything to gain...

Same brand of BCGs? I don't know.

DLA, that's a great idea. Unless there are flaws that go beyond polishing like pits or radial grooves, in which case the evidence should be apparent on the fired brass.

Since you built it you could take it back apart and reassemble.

Tried all that and didn't make a difference. I'm quite sure it isn't a gas or assembly issue. I'm convinced it is a chamber issue. I polished the chamber and loaded some ammo with a Small base die but haven't had a chance to take it out and try it . The monsoon rains have started and deer hunting came up so, it's just a matter of finding the time to get out and shoot it with the small mods I have done to see if they helped at all. Also trying to build a shop building on our new property in the meantime so I've had to prioritize to keep things moving along.

But did you lube the ammo? It is absolutely the simplest thing to try.
If you have a bad headspace problem, lubing the ammo won't do anything. If you have a rough chamber, lubing it make it run and eject nicely. If it is also undergassed, it will eject but not pickup the next round.

But if you can't make time to shoot it, maybe none of this matters.

sounds like load to hot, wouldbe if you jamming bullets into throat. LOL