The use of magnum primers is not mandatory in this caliber or any other for that matter, it is POWDER specific. If you load with W231/HP-38, they are the exact same powder, you NEVER NEED to use them.

You CAN use them and should reduce the charge weight to minimum and work your load up again. The use of magnum primers is to get hard to ignite powders going. W231/HP-38 is EASY to light off.

Now, Hodgdon is of the habit of using magnum primers by caliber. If you go to their webpage, find the data you want, click PRINT, you will see the rest of their data. It will include primer type used. It will also tell you the barrel length.

Use those tools to check on a load. All of the powder companies have a data website available. That is usually my first stop for a load. It will keep you from having to rely on "webrangers" from gun forums to help you build a load. Not the safest of practices by the way!