My first 6.5mm Grendel Project - after 3 .223 Rem AR-15s

[A.D.D. AR]

Kohoki- have you gone above 27.0 grains XBR in your load testing? If not , I would try working up in .2 grain increments to about 28.0 grains, somewhere in that range is where most guys see their best accuracy with 123gr bullets.
But once you go past 28.0 grains, pressure can spike quickly, so be careful.
-hope this helps,
mike