redgreen. thats been almost my experience, Ive seen several elk dropped very effectively with rifles chambered in 257 Roberts, 270 win and 308 win, over the years
lethality is more about shot placement and bullet construction than in brute power,
but theres very surely a difference in the games reaction to being hit well between the sub 27 caliber and over 30-375 caliber
not so much in eventual lethality, but definitely in initial reaction to being hit well, in my experience and I'm not alone in that assessment.