>>64119103
>6mm Valkyrie

Kinda exists, but is more worthwhile if loaded to a COAL longer than 2.26”. It’s called the 6mm WOA (White Oak Armament). Picrel.

Tbh the ARC series of cartridges should’ve been based on the 6.8/10mm case. Slightly smaller case head, but capable of higher pressures for the same bolt thrust (and against a stronger bolt), so performance would be mostly the same. Plus the LWRC receiver standard and 30rd Pmags already existed. I don’t understand the insistence of using the x39 case head in an AR.