I still need to do some more serious research on this, but in essence I've been wanting a close-mid range cartridge upper for a while now, and a 300 Blk flavored upper seems to fit the bill quite nicely. I'm really hesitant to make a move because I fear: 1.) ammo will be limited, expensive, and hard to find and/or won't be in stock. 2.) the cartridge will lose popularity within the next few years and fade into oblivion Now I realize no one can exactly gaze into the crystal ball and tell me everything will be alright, but can someone give me some more info on this matter that might shed light on this platform's potential permanent adoption into the mainstream AR world? Will ammo be easier to find? Are there companies soon coming out with an increased variety of ammunition? Is it being adopted by LE/Mil/etc?