"with one shot". Not without a brain or spiine hit it doesn't and a 223 would suffice with those.
I got news, 12 ga slugs don't always stop adrenalized, 100 lb DEER, and a 45-70 is 405 grs, 1500 fps. 12 ga is 440grs, 1400 fps, with over 3x the "frontal area" of the .45 bullet. so those who "think" 45-70 is so great are simply IGNORANT of the FACTS. Ditto those who "think" .45 ball is such a great "manstopper". They've been reading too many bs stories, that's all.