I would go with the 300 gun jackets soft point or hollow point. I shoot both from my TC Contender Pistol in 45-70. I load with IMR 4198. My loads are running approx 1300 fps through chrono. It is not a fast load but I have not had any Oklahoma whitetail walk off with one in them. If I can shoot in the Contender with 14" barrel, it should be a great load with the rifle. I shoot same load in my Sharps sometimes when others want to shoot it.
Mike