I have blown through elk ribs with the terminators ,28.5 inches and a 125 grain muzzy. A deer rib should be no match for one either. Almost all my elk are pass throughs. I like to shoot them a little high and a little farther back then most but I can catch both lungs and anything else in the way. I would shoot through a chrono and use the formula for figuring out KE. I am pushing 81 foot pounds of KE. Far above what is recommended for elk but I can be assured of pass throughs on a good broad side shot.