224 Valkyrie...newest AR cartridge from Federal

[09stanggt]

Looks like they are tweaking the design (reamer?) for the next batch?

I saw that and that would be my guess as well, the throats as reamed aren't liking the 90s. That would definitely be a deal killer for me. Also enjoyed the conversation on who makes JP's barrels for them. It's never mentioned if they actually chamber them or it's all done outside. I've never owned one of their barrels but I get the impression from their website that they have them all cryogenically treated. I think they'll have several pricey tomato stakes on their hands.

[SomeOtherGuy]

Looks like Harrison and AR15Performance has now decided to make barrels for this cartridge. See this page and scroll 2/3 of the way down:

http://www.ar15performance.com/6_8__valkyrie___cats

Coming summer 2018-
If I am going to make Valkyrie barrels that have factory loaded 90gr SMKs I plan to do it right. Many are already finding out the 7 twist barrels are not accurate with the 90gr SMKs. The barrels I have coming will be 6.5 twist.

[fledge]

ARP will be making them in 1:6.5 twist to fix the problem. There was also talk that the 1:7 twist was a known issue at SHOT but everyone wanted to jump in without extensive testing of the full potential of the round. Everyone but precision firearms currently has 1:7.

Additionally, the 22N won’t do the 90smk which is what sets the valkyrie apart.

[constructor]

This is what a major mfg told me about 3 weeks ago. "The first chamber design was having pressure issues with some ammo so they changed the design"
SAAMI has a habit of changing tested designs to random numbers when it comes to freebore. The people at SAAMI like .050" and .100" freebore just because they are good round numbers. I have seen the print BUT not sure if it was#1 or #2.

#1 short freebore-If you take a short case and put a .050" freebore in front of it and then load a little 55 or 64gr bullet in it at mag length 2.26 you are going to have pressure problems because the bullets are crammed into the lands. On the other hand .050 may still be a little long for a 90. For the 90s to work good it needs to have a really short freebore When the case is as long as the Valkyrie. The light 55s will need to be seated deep in the case. Going to extreme ends of bullets weights mean a compromise.
#2 long freebore -When stuffing a 90gr bullet in a case that isn't quiet as short as it should be the freebore needs to be really short to get decent accuracy. A .100" freebore is going to cause one hell of a jump when using 90s.
It may work great for the 64s, 69s and 77s because the body of the bullet is long enough to get the ogive near the lands while still keeping full .224 diameter body in the neck of the case. Short bullets say 55 and under may fall out of the case if loaded long enough to touch the lands.
If shooting long bullets(90s) a .050 will be better than a .100 but still may not produce great accuracy without loading the 90s long like 2.3 or more.
So the big question is which mfgs are using the first reamer design and what exactly is the freebore and which are using the second design and what is the freebore in it?
It will be interesting to see how this all plays out over the next year.

[HelloLarry]

ARP will be making them in 1:6.5 twist to fix the problem. There was also talk that the 1:7 twist was a known issue at SHOT but everyone wanted to jump in without extensive testing of the full potential of the round. Everyone but precision firearms currently has 1:7.

The 7 twist must only be a problem with bullets longer than the Sierra 90 because the 90SMK shoots great out of a 1/7 even at about 2400fps, at least out to 600yds.

[09stanggt]

The 7 twist must only be a problem with bullets longer than the Sierra 90 because the 90SMK shoots great out of a 1/7 even at about 2400fps, at least out to 600yds.

I had to go back and review when the old 90s were coming apart in 6.5 twist barrels. I've also seen, sample size of 1, a review bu someone with a Savage MSR shooting sub moa with the factory Federal and I'm pretty sure that 18" is a 7 twist.

Sent from my SM-G920P using Tapatalk

[constructor]

I had to go back and review when the old 90s were coming apart in 6.5 twist barrels. I've also seen, sample size of 1, a review bu someone with a Savage MSR shooting sub moa with the factory Federal and I'm pretty sure that 18" is a 7 twist.

Sent from my SM-G920P using Tapatalk

Years ago when they first came out a bunch of guys tried them in 1:7 twist service rifle(highpower) they shot fine to 300 but no one used them on the short line they were only used at the long line single feed. Accuracy suffered when the velocity dropped at long range. That is why Sierra changed the recommendation to 6.5 twist. The V may be able to push them fast enough to retain accuracy at 1000...we shall see soon since the barrels are coming out.

[FromMyColdDeadHand]

I talked to Brian Whalen tonight about taking a class and my son is going to shoot the demo JP-224V. I asked about what the deal was and he hadn't heard. He said his copy was a laser with 90s. I wonder if it is the thin air up here helps keep the bullet stable.

[SomeOtherGuy]

Sierra has reloading data for the cartridge, which you can preview at:
http://www.thefirearmblog.com/blog/2...-224-valkyrie/

Note that like most reloading data, the velocities are based on 24" test barrels.

Check the data yourself, but what I see is this:
55gr bullets max out at 3350fps, with most powders reaching the max load at 3250fps or less
60-63gr max out at 3150
69gr at 3100, most powders at 3000 or less
77gr SMK and TMK max at 2900fps with just two powders, most powders max at 2800 or less
90gr SMK (IMHO the whole reason for this cartridge) reaches 2700fps with a max load and just one powder


I don't want to go digging up lots of reloading data, but by memory:
5.56 NATO 55gr M193 should do 3250-3300fps in a 20" (not 24") barrel
5.56 NATO M855 should do 3080-3100fps in a 20" barrel
Mk262 and clones should do 2800fps or more in a 20" barrel
Hornady Superformance Match claims 2910fps in a 20" test barrel, both for the older 75gr bullet and the newer 73gr ELD-Match bullet

Those are all 20" barrel velocities and you would probably get an additional 50-100fps in a 24" barrel, to compare apples-apples with the Sierra load data on 224 Valk. Also by memory, Remington used to (or maybe still does) catalog a .223 Rem (not 5.56 NATO) 69gr SMK match load with a claimed 3000fps in a 24" barrel.

My takeaway: if you are mostly shooting beyond 600 yards, handloading 80-95gr bullets, this still has a clear benefit over 223/5.56, which can't load those bullets into a magazine that fits an AR15 magwell. Otherwise, the velocity gain from this case over a 5.56 NATO power load, in a shorter barrel!, is between very small and zero, and probably not worth the hassle.

Edit: I see that post #12 had similar thoughts, based on the Hodgdon reloading data that was then available.

I'm looking at the ballistics of TMK and ELD-Match bullets in a .308 and thinking I might just stick with my antique .308 for F-Class for a while.

[FromMyColdDeadHand]

I'm holding out to see what shakes out, especially with the JP barrels. What I really want to see is how real world rounds will work against an AR10 running 6.5CM. Both are lower cost options based on what I have, and then figure out if I want to screw with a gas gun or just put the money into a good 6CM bolt gun.

My son's going to shoot a borrowed JP-224V next weekend at a class, so I'll get a first hand feel. That copy of the gun is supposed to shoot 90s great.