Nothing wrong with a CoreLokt on deer...I've killed about 90 of so with it, out of my .243...When it comes to the .22 centerfires and deer, when you go from say a 55gr bullet made for groundhogs to a 60gr Nosler Partition made for deer then you go from a bullet that fragments to a bullet that mushrooms, stays together and gives full penetration on center lung shots...So it makes the .22 calibers more effective on larger game...