I guess I'll kick this off since this is hopefully the primary cartridge I want an ACR in. My hopes are its a 6.5 Grendel but I dont know if Bill and Remington/Bushy could come to an agreement. The 6.5 Is a great cartridge and I think it would give the ACR general purpose capabilities from 0-1000m. Has anyone heard anything on the caliber if it isnt Grendel? I would imagine if it was a Grendel they'd be calling it that.