6.5 Grendel vs 224 Valkyrie

[sarky]

We all have probably seen this and how writers are comparing the 2 cartridges. But has anyone seen a variation on the .224 Valkyrie, ie 6.5 Valkyrie?

[grayfox]

There is I believe a wildcat 6.8x6.5, which is essentially what you're proposing...
the taller, narrower powder stack would seem to reduce the burn efficiency...

[bj139]

Ar15performance used to sell this wildcat barrel with the name Six5. I bought one used. It is a simple neckdown of the 6.8 SPC where I think the Valkyrie is shortened also. I only shot 10 shots through it as shown below.
I had to grind down the shellholder to make the cases with a 6.8SPC bushing die and used a .285 bushing.

[sarky]

True, but because the case he'd is smaller, you can raise the pressure with less fear of shearing bolt lugs.