Does p[rimer brand matter?

[denton]

I have measured peak pressure on a few different loads, with both standard and magnum primers. I have yet to find a load where a magnum primer increased peak pressure. I'm not saying it isn't out there. I just haven't found it yet.

The original claim of magnum primers was more uniform ignition of slow burning powder, in very cold weather. And I don't know if that claim is true or not, either.