Real question... Can magnum large pistol primers be used in place of regular large pistol primers without too much difference on the performance?

Curiosity question... What are the differences between Sm pistol vs Sm rifle and Lg pistol vs Lg rifle primers? Although they shouldn't be interchanged, can they safely?

Regarding your first question, I settled on Winchester large pistol primers for all my pistol loads that take a large pistol primer. They can be used in any application requiring a standard or magnum primer. 10MM, 45 Auto, 45 Colt, and .44 Magnum are the applications I have them in. Don't start me on small pistol for 10MM and 45 Auto...

As Chad said, yes, you can use them interchangeably in SOME instances as long as you adjust powders accordingly. But, why would you? IMO the round is more likely to perform better when using the correct components.

I don’t want to interchange pistol and rifle primers. I was just curious. This why I said curiosity question. As far as magnum primers. I bought a lot of reloading components, it came with 200 Lg magnum pistol primers. I don’t los anything that requires them. I just load 45acp with lg pistol so wanting to know about the magnum primers.

Trade them to a single action magnum reloader.

This is it. I’ve loaded a lot of pistol rounds with SPM and SR primers that didn’t need it. I’ve known guys that would only buy SR primers so they only had to keep track of one size for their competition ammo for 3 gun.

Rifle primers small and large have harder cups than pistol primers and need a harder hit to ignite. I have used large pistol primers in my 444 Marlin rifle but it is not a high pressure rifle cartridge and they did fine. You just have to know what you are dealing with.