Both are effectively 22 caliber variants of the 6.8 SPC. The 224 Valkyrie is far better executed than the 22 Nosler, however. The Nosler is - effectively - a rebated rim 6.8 spc with a 223/5.56 sized 0.378” rim, such it uses standard 223/5.56 bolts, but 6.8 SPC mags. It’s a longer case than standard 6.8 SPC, with the same 1.75” trim length as 223/5.56. Execution on the brass has left a bit to be desired, and a lot of folks have had issues with rim dimensions for extraction. The long 1.75-1.76” case doesn’t leave room for the long, high BC, heavy weight bullets to be seated to mag length, so it’s limited to ~77’s, just like 223/5.56. Equally, standard twist for the Nosler is 1:8”, too slow to run the heavyweight bullets even if they were single fed instead of mag fed. Of course, a custom barrel can be ordered with any twist, but the mag length issue remains. The Nosler made a “past generation mistake,” in my opinion, designing the case for under weight bullets - fast and light only works so far, as poor BC’s shed speed like crazy (odd to consider the 77SMK a poor BC after all of these years shooting it for long range in 223, but the 77’s .372G1 does look pretty lackluster beside the 90SMK’s .504G1!!). Like most of the Nosler cartridges, ammo and brass are only available through one (or a select few) companies. Nosler operates similarly to Weatherby in that way - their rounds are effectively proprietary, which will always limit their market. I personally think the “mix and match” game they played with 6.8 spc cases and 223/5.56 dimensions was a silly attempt to pander to folks who don’t know any better. They run the same 55kpsi and same internal head face area, so they have the same exact bolt thrust, but the Nosler has a smaller rim, which is easier to malform, causing extraction issues.Any opinions between the Valkyrie vs Nosler?
Alternatively, the 224 Valkyrie pushes back the shoulder of a standard 6.8 SPC case and trims at 1.58-1.60”, leaving plenty of room for the big 80-90grn 22 cal bullets with super slippery BC’s, but still has the case capacity to get them downrange in a hurry. The Valkyrie launch didn’t happen without a few stumbles. There were some bad reamers out there, and a lot of folks have claimed the 90’s need a 1:6.5” twist because the early Federal 90grn loads were terrible (now replaced), but there have been plenty of us shooting 88-90’s from 1:7” twists successfully (getting a 1:6.5” won’t hurt anything, but it does limit your options for sourcing your barrel). Brass and barrels are more widely available for the Valkyrie. When the Valkyrie dropped a year after the Nosler, it was clear, the end is coming for the 22 Nosler. Federal and Savage pushed products widely to market with blistering speed, and the chambering was pushed out by every custom barrel maker in the game, and several other MSR makers. The Nosler does have a slightly bigger case, so with the same bullet weight, it has a 50-100fps advantage, but the higher BC’s possible in the Valkyrie start making up the difference downrange in a hurry (the Hornady 88.5 ELD is awesome!).
To be honest, I’m not really a fan of either, but as a fan of all things pertaining to long range AR-15’s, the 224 Valkyrie is the better option. Admittedly, there’s really nothing I can do in the coyote fields with a 22 Nosler or 224 Valkyrie that can’t be done with a 223/5.56 AR within 100yrds or so - but the brass for Nosler and Valkyrie costs more and is less available, they eat more powder, and they burn out barrels faster. So these are an interesting novelty for me, and I’d rather have a 6mm Grendel variant (mines a 243LBC, but Hornady is about to drop a 6mm ARC), but if CO says 22cal and less to avoid deer hunting confusion, the 224 Valkyrie is the one I’d pick.