My BK 92 is a MK85 with a cheap synthetic stock. 2 50 gr pellets and a 300 gr saboted bullet work great and I cannot imagine why you would want to increase recoil and expense except maybe if you were hunting dangerous game or shooting over 125 yards. You are 100% correct in going to the 300 gr bullet for hunting as it gives much more energy downrange. May I suggest the Barnes 300 gr Expander? It is awesome on deer. After checking out all the new muzzleloaders I bought a Knight Bighorn, 50, 22"barrel and have outfitted it with a Williams apeture sight with the shotgun apeture mounted where the original rear sight was ( this is for 50 yards and under hunting with adequate light ) and a Leupold 3x9 mounted on Leupold Quick Release Rings for longer range hunting like out of a blind and in very poor light conditions. Enjoy your MK as it is a very good gun. I use the secondary screw down safety often and Knight is the only company that has this great feature.