I shoot three shot groups with hunting rifles because I almost never shoot more that three time at an animal. However if my three shots groups start to change for the worse then I may have to change something which might require more shooting. Rifles like my 22-250 have shoot more five shot groups because I require more pinpoint accuracy from a Varmit round. Also if I want to use it for deer, I have to know it will hit exactly where I am aiming.