For your 7 Mag, the Federal 215 and Remington 9 1/2 M primers are the 2 hottest primers. A CCI #250 would also work, but is slightly less hot. A standard primer will "work", but I would recommend a magnum primer with a slower burning powder. I know shooters who use a standard primer for their magnum cases, and they work fine.
Just to clarify,,,the Rem primers seat softer than the Federal and CCI primers. The brass pockets were still tight with other primers except Rem primers. I think the Rem primer diameter is a little smaller if I am not mistaken.
I just feel a lot less pressure when seating Rem primers, does anyone else feel the same?