Ive yet to recover a hard cast gas check bullet in the 400-450 grain range fired from a 45/70 or a 450 marlin rifle so far theres been an exit wound every time
even the 355 grain versions generally exit elk
https://www.midwayusa.com/product/6...8-diameter-405-grain-flat-nose-gas-checkhttps://thebiggamehuntingblog.com/hunting-cape-buffalo-with-the-45-70-government/https://forty5seventy.wordpress.com/ generally load those bullets to a 1800-1900 fps range