I use Fed GM215M in all of my cartridges that use large rifle primers. I also use Quickload for all of my load development these days. When working a new load I play with powder selection that gets me to 100% fill and preferably 100% powder burn within the barrel. many of these will be over modern book max loads. I've never had a cartridge show concerning over pressure signs using this method even at max or slightly over max loads.
I've not seen any evidence that Mag primers make enough of a pressure or velocity difference over standard primers to be concerned with.
I've not seen any evidence that Mag primers make enough of a pressure or velocity difference over standard primers to be concerned with.