A 300BO is balistically similar to a 30/30 or a 7.62 x 39. It is a plenty good deer getter at 200, maybe 250 yds. If you need to take a shot longer than that I don't recommend it, but the recommendation to build a pistol is the way to go. For a kid the blackout recoil isn't bad at all, and being very efficient you only need about 10" of barrel to get most of the velocity it's capable of (16 really doesn't get you much more as the powder is all burned at about 9"). My 10.5" pistol is only about 26" long and weighs in at about 6 lbs with glass on it. I would have LOVED to have been hauling that around vs the 12lb .303 Brit my father first gave me to hunt with. The Sig brace will add about another lb but it's still short and easy to maneuver, and offers plenty power within it's effective range. So unless 300yds or more are the regular where you hunt the blackout is a fine round.