I no some people that use magnum primers on standard calibers and their rationale is they are using slow burning powder or ball powder in a big standard case and they will be shooting at close to freezing temperature and want to make sure the powder is lit right. I don' t agree with this but they certainly haven' t been bothered by it, my only concern would be what happens when you fire the gun and the temperatures are in the 70' s and 80' s...