You can take a 378 Weatherby from ~1500 fps with a 249 gr lead slug to 2900 fps with a 300 gr. RN solid using data published in Lymans Manuals. That would be lever rifle 44 mag power (deer rifle) to Elephant rifle power range. Is that enough power range for you? That would be ~ 1200 ft. lbs. to ~ 5600 ft. lbs. for a delta of ~ 4400 ft. lbs.