DDS444, Primer use is dictated by the powder being used. H110, WW296 require the use of Magnum primer and a firm crimp for proper combustion of the powder. Powders like 2400,
AA#9 require the use of standard force primers. Best to check with the powder data available and choose from what the manufacturer's advise! I have a stock of both standard and magnum primers for all my loading. Powder choice tell's me which to use.