I’m looking at picking up another Upper in 6.5 Grendel. I’m looking for something with more umph than a 5.56 to hunt with and use for SD purposes, if I ever need something that will reach out beyond 300-400 yards. I Really do not like the size and weight of A.R. 10 rifles… So going to stay with traditional A.R. 15. 7.62 x 39 is also appealing, but really,really falls off after 200/250 yards. Thoughts on the 6.5 Grendel..?? Ballistics +ballistic coefficient are good & supposedly so is the penetration! Drawbacks,other than ammo is more expensive than 5.56?