The Grendel is a weird one to me.
Another one of these wildcats that do a tweak here or there to have some differences that sound appealing on paper but at the end of the day don't do anything.
They're meant to be more accurate then the 5.56 while keeping the same cartridge length. Basically they chopped off the bottom of a 6.5CM, so you have these high BC projectiles but not as much powder driving them and more limited range. Less recoil, but whatever, it's not like the 6.5CM is a savage cartridge.
Compared to the 6.5CM you basically trade range and performance to have a cartridge that's a cm shorter shorter. How is that cartridge being shorter useful, really?