.224 Valkerie conundrum

[Pappabear]

It is supposed to be a known issue. For those in the know.

PB

[markm]

Commonplace or just certain combos?

Specific bullets perhaps? Makes perfect sense.... Of COURSE you can't spin bullets at that RPM and expect no issues....

[DCB]

I looked back at some of the reading I was doing and figured out that I was thinking of a similar (but different) issue between a lot of these new "shove a smaller diameter bullet in a fatter necked down case" trends. So I was slightly off, PB.

The .224 Valkyrie has been plagued by a number of barrels being too slow in twist to stabilize the heavier 90gr projectiles at the velocities they are pushing it. Someone smarter than me on SH commented that the .224 Valkyrie was a great way of breathing life into dead inventory of "match grade" 223 barrels.

Many manufacturers took their old inventory and re-chambered the dead stock of 1:7 .223 barrels with the new reamer for .224 Valkyrie and suddenly they had a new hot product on their hands; but this resulted in a lot of .224 Valkyrie barrels floating around with insufficient twist for the .224. JP put out a memo even acknowledging this:

“Dear JP customer,
If you are receiving this email, it means your current order for one of our JP Supermatch™ barrels in .224 Valkyrie is eligible for fulfilment in our first production run. But, because of the unforeseen complications of developing barrels for a brand new caliber like this, we wanted to contact you before completing your order.

After final testing of these barrels, we have discovered that accuracy specific to 90gr. Sierra Match King and the 90gr. Fusion hunting ammo is only mediocre. These results are not up to the JP standard, and as such, we cannot honor our accuracy guarantee with this 90gr. ammunition.

However, the Federal varmint load using the 60gr. Nosler Ballistic Tip and our personal test loads using 77gr. Sierra Tipped Match Kings shot well from these barrels. With the 77gr. Tipped Match Kings, we achieved maximum velocities in the 3000 ft/s range. This compromise of utilizing lighter projectiles with much higher MV and slightly lower BC may actually result in higher hit probabilities within the effective range of the cartridge. This is particularly the case with unknown distance targets.

At this point, we want to offer you the choice of confirming your order and receiving one of these first JP .224 Valkyrie barrels. Alternately, you may opt to wait for our next run of barrels with further design changes to improve the performance of the 90gr. bullets. The choice comes down to your choice of application and ammo.

Please respond to this email with your preference.

If you choose to wait, your order will still be fulfilled in the order it was received as soon as the new barrels arrive and are tested. If you choose to wait, we expect to ship your order sometime in May.

Sincerely,

JP Customer service team"

and for what it's worth, the post I was confusing myself with about the jackets spinning off of bullets is from the 22 Creedmoor, where they are pushing 90gr bullets to 3000+fps, exceeding the 300k RPM threshold and disintegrating bullets in mid air

Similar issue seen here:

[markm]

So perhaps that 88 gr was spinning too slow and simply not stable. In any case, the accuracy was not acceptable at 100 with either load.

I have an AR barrel that will (for whatever reason) spin 55 gr hornady soft points into oblivion.

[Vegas]

Interesting stuff. I have been arguing with myself whether I wanted to reload for another caliber. I have 223 gun I could rebarrel. If the heavy stuff is going to cause problems, not much point in my mind of getting involved.

[Coal Dragger]

Interesting thread look forward to updates as they come in. Curious what twist rate will be needed at given velocities to stabilize the 90gr bullets, I’ve considered a .224 Valkyrie rebarrel on one upper but have been letting others get it figured out first.

[markm]

For what it's worth, the gun cycled good. He was running some sort of 6.8 spc mag.

[Pappabear]

The guy called Wilson Combat and was told to try lighter bullets and said they heard of these stories. They said get back to them if it doesn't work out and they would make good on whatever needed to be done . Good call by WC.

I agree, if you have to shoot 55-62 grain pills then why even have the gun. Seem like this caliber got ahead of itself for a minute.

[BC98]

The .224 Valkyrie has been plagued by a number of barrels being too slow in twist to stabilize the heavier 90gr projectiles at the velocities they are pushing it. Someone smarter than me on SH commented that the .224 Valkyrie was a great way of breathing life into dead inventory of "match grade" 223 barrels.

Many manufacturers took their old inventory and re-chambered the dead stock of 1:7 .223 barrels with the new reamer for .224 Valkyrie and suddenly they had a new hot product on their hands; but this resulted in a lot of .224 Valkyrie barrels floating around with insufficient twist for the .224. JP put out a memo even acknowledging this:

JP’s letter never said anything about twist rate not being sufficient to stabilize the projectiles. The letter said that the 90gr bullets were not meeting JP’s accuracy requirements. I’ve shot several JP barrels that were sub-MOA with the 88gr ELD ammo and SOME lots of 90gr Gold Medal. Also, both Frank Galli and Brian Whalen have taken JP barrels (with 88gr ammo) out to 1500 yards. JP’s current barrels are still 1:7 twist.

Also, nobody is just rechambering .223 barrels as .224 Valkyrie without major rework. The Valkyrie case is shorter and will not completely replace a .223 chamber. To change an existing .223 barrel, you would have to spin off the barrel extension, cut .060” to .080” off the back end of the barrel, reinstall the barrel extension (timed with the existing gas port), and then finish the .224 Valkyrie chamber.

Federal put the 90gr Gold Medal load on a temporary hold while they worked with Sierra to improve the 90gr SMK projectile. Within the last month or so, Federal has started to ship the improved FGMM rounds out to the public. Initial reports are that accuracy and consistency have greatly improved.

[markm]

Also, nobody is just rechambering .223 barrels as .224 Valkyrie without major rework. The Valkyrie case is shorter and will not completely replace a .223 chamber. To change an existing .223 barrel, you would have to spin off the barrel extension, cut .060” to .080” off the back end of the barrel, reinstall the barrel extension (timed with the existing gas port), and then finish the .224 Valkyrie chamber.

Perhaps they were trying to move barrel blanks.... not .223/556 completed AR barrels.

None the less, I'd like to see what this same barrel would do with a few various lighter bullet loads.