Use whatever you want to use (243 and above are best) and with a heavy for caliber, bonded or mono bullet and have the patience to wait for the animal to die or keep shooting til they go down. Personally, I have killed elk with 7mm's, 338's and 300's. All with handloaded NP's and all succumbed in their tracks or within feet. Switching to AB's and ELD-x for the higher BC. I'm 5'7, 140 lbs, 67 years old and am a bi-lateral amputee below the knees. My point is, if you have a reasonable caliber you can go after elk. Beyond 243, anything will work but YMMV and you may want more gun as insurance. Just make sure you can shoot it straight. Good luck.
