Excuse my ignorance, but is it an extruded or ball powder?
No such thing is available here, but if it's ball powder, the brass is SRP, then, yes, you would want a magnum primer.
If it's extruded, even if SRP brass, then I would think a magnum primer is not required.
If brass is LRP, then no magnum primer is required either way.
I will say, I test both standard and magnum in both sizes regardless of case size….there is ALWAYS a clear winner on target.
Cheers.