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Magnum primers typically are a bit hotter then standard (though not all). You should be alright as long as you are not loading at the top of the load data. Even then I would drop charge weight about 10% and work back up.
I have switched between magnum and standard primers and have not experienced any difficulties but YMMV. Drop the charge weight down some and work back up better to be safe then sorry. You may also find slightly better grouping as you are using ball powder and the magnum primer should burn better.