Mule Deer can answer this better than me, but I haven’t found the need for magnum primers with either Big Game or Hunter in 7x57 loads. It may have something to do with the fact that the charges aren’t huge - all less than 50 grains - but again, John can give a better answer.
"An archer sees how far he can be from a target and still hit it, a bowhunter sees how close he can get before he shoots." It is certainly easy to use that same line of thinking with firearms. -- Unknown
