RE: is the 454 big enough to harvest elk
The book says that to take a deer cleanly you need roughly a 1000# of energy to be adequate! For elk sized critters you need 1200-1500 # ---Of course where you hit an elk can determine a fatal shot or not. A 30-30 rifle with a 170 grain bullet delivers 960# of energy at 200 yards a well placed shot in the heart lungs will do the trick, yet this is well under what the books recommend!
One must use good sound judgment on shot angles & distance both before pulling the trigger! (grin) It appears you have a good 100 yard gun there, use good bullets & they will get r done!!
ElkNut/Paul