Would be good to know if you are running this in a gas gun or bolt gun? If its a brand new build or you already have parts on hand. I think the 7.62x39 severely hinders your abilities as a hunter in making ethical / efficient kills 100% of the time. If you are building a gas gun, the 6.5 grendel would probably be my pick, especially if you reload. Plus with a 6.5 caliber you can shoot 130ish grain bullets which is a on the higher end of the spectrum vs 7.62x29 you are mostly shooting <130 grain bullets which causes a major loss of sectional density for the 30 caliber family, plus combined with low velocities, I personally think there are a ton of better options. If you are building a bolt gun, your options expand even greater, you could use an old remington or savage action and do a pre-fit barrel and make a 16" 300 savage or 257 roberts / bob. I am building a 16" 30BR later this year for a "brush" type of bolt gun. I predominantly shoot bolt guns, so if you have any questions feel free to hit me up. Gluck with the build!