Federal returned the call first.
Here is what they had to say.

In order of "hotness", brisance, coldest to hottest it goes like this:
The order is the same for either large or small primers.
Standard Pistol Primers/Match Grade Primers
Magnum Pistol Primers
Standard Rifle Primers/Match Grade Primers
Magnum Rifle Primers
"50cal" Primers
The technician also stated that the other difference is cup thickness. Not so much hardness but thickness. The thicker primers are rifle ones and they are meant to withstand the higher pressures of most rifle cartridges.
He said there are problems going either way. Light strikes with rifle primers in handguns and pierced ones in rifles with handgun ones.

I will post other information as it becomes available.