We have taken Elk with 257 Wby 110 accubonds usually a lot closer, 25's are great for Deer , Antelope size animals, but Elk is a different ball game. I really don't go all out for pure energy figures I also look at momentum, bullet dia, sectional density, along with the standards velocity, BC's, bullet constructon, and mostly from me and my friends past experience, etc. the perfect shot almost any animal will go down, BUT who always get's the perfect shot, not me that's for sure. we have friends and their kids that shoot Elk with 243's and it's mostly 150 yds and under and they are good shots, I won't do it I think it's too light of a bullet really same with the 25's until just lately they are starting to get bullet's in the 130's. most of the family used 270' Win's , my daughter and son-in law use 30-06 and 7mm Rem mag. the 270's in our case are good to 400 yds give or take and yes we use range finders have for years, started with the old Ranging 1000's what a pain they were. now days we have Leica, a couple of Vortex , Had a Leupold which was pretty good until I went to my current Vortex Fury AB 5000 bino/rangefinder. one friend now gone used a custom 25 x 300 ultramag at 400 yds on a big bull 1 shot dead. now days my son and I are shooting Elk at much longer ranges and both use 300 WBY's with 180 gr TTSX @ 3150 fps. My thought on Elk hunting in general and I hate chasing Elk down deep canyons basically shoot them until they stop I don't care if they are on the flat in a big meadow or in deep heavy timber or canyons, use enough gun to get them down, if they are on the top of a ridge with a canyon below I tell the family or friends I maybe hunting with aim for the shoulder and anchor them, you are going to take out the shoulder blowout 2 or 3 ribs and front part of the lung, yes you are going to ruin a bit of meat, but you are not going to be there for a couple days getting an Elk out. been there done that more times than I would like. one year in Eastern Oregon with my Dad and his hunting buddies I shot a nice Elk on top perfect shoulder shot with my dad's 270 win I lend my 270 to another fried because his scope froze, anyway I used my handloads 150 gr Sierra bullets blew up on the shoulder maybe 70 yds or so, dropped then got up and shot again in the same place , elk got up and ran 2000 ft down a slope and 800 ft elevation drop, dad's buddy had 5 - 1000 ft rolls of 3/16 th stainless cable so we reeled out 2000 ft of cable clamped together it took 7 of us all stinking day to get that elk out. my son shot a big bull about a mile in on a ridge in the snow and downed trees from a big fire with a 270 Win not a long shot took 2 days to get it out boned out on the last trip out my wife slipped and fell in between 2 downed small trees and broke he ankle very close to the truck, thankfully guy's had a side by and drove a few yds got her in the side by and into the truck loaded her and to the hospital for surgery took years to heal, these aren't the only times we have a lot more experiences with getting Elk out, sometimes I think I'm getting dumber especially with elk we still do things we shouldn't. we all got to do it once and then you learn maybe. moral to the story use enough gun , good bullets , aim good, shoot them till they drop, and shoot them in a place you can get them out .