For the slr build I reload so there is a moot point
So what are your thoughts
More a coyote gun
6.5 Grendel is more established. There is a decent supply of factory ammo as well as reloading components available. It will work for coyotes and it is capable of doubling as a medium sized game cartridge. However there isn't much choice for a 6.5 varmint (coyote) specific projectile such as the v-max or nosler ballistic tip.
224 Valkyrie interests me more when you limit it to a coyote or varmint cartridge. There is a wider range of suitable bullets available and, since you reload, I can see the Valkyrie offering you the ability to load some awesome coyote rounds.
I've often thought about loading the Valkyrie with some lighter 50 grain v-max pills. I think you could push them very fast and end up with a decently flat shooting round that would put the standard 223 rem to shame. My only concern would be trying to push the little pills at high speed out of a Valkyrie barrel that has the standard 1in7 twist. If I only wanted to shoot 50-60 grain pills with coyotes being the main purpose I'd have my Valkyrie barrel made with an 8 or 9 twist.
If coyotes are your main purpose for building this gun I think the Valkyrie is more suitable. Also, Federal has a 60 grain v-max round that offers decent ballistics and hits much harder than a standard 223.
Only problem as of now with the Valkyrie is the availability of factory loaded ammo or factory brass. The bolts and magazines are not an issue to find.
For a long range paper puncher or for a deer gun my vote goes to the 6.5 Grendel.
For a coyote gun my vote goes to the 224 Valkyrie. I say push them fast and flat. Forget about the 90 grain paper puncher pills.
The Valkyrie may just be the round that gets me into reloading.