Howdy, Jarrod! I know when you start shooting out of a blind the first time, the hardest thing to get used to is the "tunnel vision effect" of shooting from the dark interior, through a hole, into the bright outside. You gotta practice that so it doesn't throw you off. Things appear either further/closer than they really are in that situation. Also you need to practice shooting off your knees, which you are probably already used to since you are a open country hunter, but you need to practice shooting while sitting on a short stool/bench, which you may not be used to. In either case, the 68" will be plenty, but standing up and shooting from in the blind will be very tight. Hope this helps.
So, when you heading overseas? We might stop and see you if you are around during the last two weeks of July...