So, I bought a Valkyrie (part 2)

[Mobuck]

Before even shooting the first Valk, I bought another on a spur of the moment (it's too cheap to pass up) sales pitch. At $265 delivered how can you go wrong.
Since the second upper was just lying there today, I wiped the bore, mounted a scope, and took it to the bench. Immediately, there were "issues". The Federal 75 grain FMJ I'd bought for break-in absolutely would not chamber and I barely managed to extract the wedged rounds. OK, this isn't what I expected so I tried the Federal Premium Varmint 60 grain BT ammo. By loading the round in the chamber and tripping the bolt release, I could get the bolt to go fully into battery but still could not extract the loaded rounds. I did manage to get 7 rounds chambered and fired. Pretty surprising accuracy in the "cloverleaf" range.
I was running out of time so called it quits and retreated to the workshop to assess the issues. After a bit of grumbling and cussing, I pulled another new BCG from the parts box and tried it to see if there was a difference. Guess what, the different BCG chambered and extracted both of the Federal rounds w/o strain. To late for renewed accuracy testing but I don't see why there should be much change.
I sent an email to the seller describing the issues and hoping I can just return the bolt or BCG for replacement.
Bottom line: If this thing continues to shoot this good with the varmint ammo, I'm going to be ecstatic.

[Metal god]

What's the parent case 6.8spc ??? It's an interesting round for sure and I'm considering getting one .

[Mobuck]

Yes, casehead is same as 6.8.
It seems headspace is a wee bit tight on this unit. I did find that a PSA bolt would go fully into battery on both types of ammo and a Brownells(?) bolt will lock up on the Federal Premium but not the American Eagle. Another bolt I have won't close on either.
I'm getting the idea that mixing of parts on this chambering isn't going to work like it does on .223.
Still waiting on response from the retailer. I'm going to wait for their decision before testing with a different bolt but I can guarantee that the bolt shipped with the upper hadn't been checked with the chamber. It was "packaged separately" and didn't have a mark on it. I'd be OK with just replacing the bolt if that's the problem. If they don't make the deal right, I'll give them a big "frowny face" and tell everyone to "stay away" from these guys.

[ed308]

What's the parent case 6.8spc ?

.30 Remington

In the process of building mine. But realized I'm missing a couple parts (ie: Selector Switch and Buffer Retainer Spring? And I thought I had everything.

[Metal god]

.30 Remington

How available are those ? Hmm not that it matters , necking down a .30 cal to .224 would be a long way imo . Where are people buying the brass for the Valk to reload ?

[jetinteriorguy]

Starline makes brass.

[Mobuck]

For my intent, the Valk is not a high volume shooter. I can easily live with an accurate factory load. Some of the "stuff" people are doing with this round is a wee bit edgy IMHO.
Update on the OP:
I got an email suggesting I "try a different BCG". Well, I've already done some test fitting and will test fire a few rounds with a different bolt today if time allows. The barrel itself is showing acceptable accuracy with 60 grain BT's if I can get 100% functioning and safety.
FWIW
I did get a chance to shoot my 18" Valk and it's really accurate with the econo-grade 75 grain FMJ and under MOA with the 60 grain BT's. Problem I see with it: I'm not gaining as much velocity as I'd hoped vs a 20" .223 with 50 grain BT's. In the under 400 yard ranges, it's a bit disappointing to see so little advantage.

[ed308]

Where are people buying the brass for the Valk to reload ?

Starline or Hornady makes it. Stag has stated the Hornady brass is the better of the two.

[Metal god]

I just went and looked at the powders used in the cartridge . I have and use most of them along with the bullets . I think I may pick up an upper . I have my CMP NM lower with national match trigger in it I can use . That might be a pretty cool set up .

[stagpanther]

Well--here goes. Just my experience; I'm sure there are plenty of people that will say I'm completely full of it.

Mobuck--don't be surprised by the "malfunctions" of the 90 gr factory fusion stuff. measure the COL and guess what--it's already under the typical 2.26 you get for the platform as the "average" (at least the box I bought did). The shoulder is set back compared to the 6.8--so to some degree you might get what I call "the Grendel effect" meaning the "accuracy" of the chambering can affect the bullet path--partially the result of very high SD/BC bullets seated long forward of the case mouth. That's why--my guess--you had the stiff resistence in trying to extract the chambered cartridge, and why it "went away" with a different BCG. The BCG might be the difference--or it can simply be how well the combination of the BCG works with the particular magazine (I think cavity back's are about the best in terms of over-all reliability across a wide range of cartridges).

Now here's the kicker that I think will surprise everyone--when I called Harrison and told him about it even he said he could not explain what I found (although the chances are good he was just being polite maybe ) When I finally got his "in spec" Valkyrie chambered barrel which has not only the shortened freebore but the "tolerance stacking" in all chamber dimensions is a bit less than the other two barrels I bought--I found that reliability in chambering actually went up! This was easy to verify with Berger 90 gr vld's seated long as these are very prone to jamming and/or getting knocked about upon chambering in the long freebore barrels compared to the shorter one.

Another way you can verify this phenomenon is to use a comparator to measure your distance to where the base of ogive engages the lands--then simply make a dummy cartridge and test drop the bolt on it--even when the comparator shows some remaining jump to lands, sometimes the extracted cartridge will show signs of a wedging force on the side of the bullet just forward of the case mouth.

[stagpanther]

Problem I see with it: I'm not gaining as much velocity as I'd hoped vs a 20" .223 with 50 grain BT's. In the under 400 yard ranges, it's a bit disappointing to see so little advantage.

Yup--why pay for reinventing a good Wylde/223? That's why I personally am not interested in anything much under 90 grs--the only bullet I can think of that's really close to "optimal" for the valk under 90 gr's is the 88 eld. Sure you can drive the smaller ones fast and acceptably accurate--but now you're in the same territory as a long-barreled conventional 223.

[Metal god]

Yup--why pay for reinventing a good Wylde/223? That's why I personally am not interested in anything much under 90 grs--the only bullet I can think of that's really close to "optimal" for the valk under 90 gr's is the 88 eld. Sure you can drive the smaller ones fast and acceptably accurate--but now you're in the same territory as a long-barreled conventional 223.

I've been researching this cartridge and it does seem to give very little extra when shooting the heavy bullets like the 69's , 75/77's but the 90's do seem to be getting better .

I think I'd like to understand the chamber design a little better .Stag I agree with you that performance wise the valk does not really seem to do much more/better then the 223/5.56 cartridge . It does appear with the shorter head to shoulder distance you should be able to adjust seating depths more to adjust your hand loads while still loading to fit in a mag ?? When I load my 223 wylde AR's or the 5.56 ones . The 69gr and 77gr bullets are seated to 2.260 period . There's no real adjusting the seating depth to get better accuracy because you only have one direction and that's deeper . Most of those loads I use with the heavier bullets are compressed a little so seating deeper is not really an option . This means the only way I've found to dial in my loads is with powder charge increments .

That said . the fact you can load a 90gr bullet to 2.260 and it still feed from a mag with this cartridge means there should be a good bot of room to play with seating depths with the 69gr and 77gr bullets . Is it this type of thing that makes this cartridge a little better then the 223 ? I don't know the chamber specs but would love to be able to seat my bullets closer to the lands then I currently can with my 223/5.56 chambers .

I like the idea of having a cartridge that fits in a AR mag that will also allow me to dial in a load a little better then I can with powder charge alone . Or am I misunderstanding the chamber design of this cartridge ?

[stagpanther]

Or am I misunderstanding the chamber design of this cartridge ?

Join the long line which apparently includes lots of manufacturers.

It all started in the spring when the industry basically flooded the news media with reports of the "Creedmoor killer"--the 224 valk basically replicated it's ballistics (other than energy) by putting a 224 bullet out to 1300 yds and staying supersonic all the way. Hornady's 88 eld should theoretically be able to do that as well as the 90 gr MK and vld as well as the excellent 95 gr MK. All of these bullets can be seated well past the 2.26 COL--even in the "short freebore" barrel that I bought from ARP. That's what gives you "room to play" with additional case capacity and getting close to the lands. Getting there with the SAAMI spec 2.26 COL--gonna be tough, don't know if anyone's succeeded in that yet. That said, the inherent performance edge to get there over the other 224 variants is there in the valk--it's just not what Federal pushed out the start gate in the spring, along with what appeared to be a crop of chamber reamers that nobody seemed to know who really checked to what standards (until H did).

That said . the fact you can load a 90gr bullet to 2.260 and it still feed from a mag with this cartridge means there should be a good bot of room to play with seating depths with the 69gr and 77gr bullets

Not exactly--the smaller, shorter bullets by virtue of where their ogive base is can only be seated so far out--definitely not as far as the bigger ones.

If you get cavity back's magazine with the front cut-out you can basically go all the way in COL to where the only limitations are the depth of the magwell itself and where the bullet nose can hang on the extension's edge with bullets like the bigger MK's. A word to the wise after firing thousands of cartridges through the magazine--and which I suspect affects almost all magazines to some extent: I've noticed that magazines can "swell" side to side. This can alter how the stacked cartridges align in the magazine and might "all of a sudden" manifest feeding and cycling issues in the gun that otherwise weren't there previously.