Like said above, magnum primers are powder specific, not load specific in handgun ammo. Hodgdon will use a magnum primer in all their .357 Magnum loads and use only standard primers in all their .38 Special loads even though they are using some powders that work much better with a magnum primer like HS-6 in the .38 Special.

When loading hard to ignite slower ball powders like HS-6, HS-7 and H110/W296 use a magnum primer. W231/HP-38 is a fast enough ball powder so as not to require a magnum primer. I use a lot of W231 in the .38 Special, .38 Special +P, .357 Magnum, .45 Auto, .45 Colt and a few others and all are loaded with a standard primer with very good results, no unburnt powder and low SD numbers.

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