I’m looking to build a NON-5.56 general purpose AR15 rifle that I can also hunt deer & coyote with. I’m trying to keep barrel length as short as legally possible without completely neutering the cartridge capability. Possible shot range is 20-300 yards and I hunt tree stands and blinds. So far I’m considering 7.62x39, 6.5 Grendel, & 6mm ARC. Big bores like 450 Bushmaster aren’t an option as my daughters may use it as well. Are there any other calibers I should be looking at? What caliber and barrel length are you guys using?