Sure. But if you have worked up to a maximum load with any particular bullet/powder combo, you should cut that load back 2-3 grains and re-work it, since magnum primers MIGHT increase pressures some if you were to use the SAME powderr charge (but that doesn't ALWAYS happen, either!!) I've used magnum primersin a 7X57mm when I ran out of standard primers, and had no problems whatsoever.