Are Small Pistol Magnum & Small Rifle Primers Safe in 9mm?

[The_Shadow]

Are Small Pistol Magnum & Small Rifle Primers Safe in 9mm?  What about 10mm with small rifle primers?

https://youtu.be/NGVRGsoOr6k

[Graybeard]

Looks like they can be used safely, but they aren't the same.

I found this guy's video interesting. He seems to have gotten the opposite results, concerning velocity, in .357, using H110.
https://www.youtube.com/watch?v=Pk-mzblzcPo

[fltbed]

Back in the 90's, USPSA shooters routinely used small rifle primers in 38 Super and 40 S&W ammo.  The only detectable drawback is breach face pitting.

[blaster]

I have loaded plenty of small rifle primers in 9mm and other calibers. I shot the 9mm out of 5 different pistols, both striker & hammer fired with 0 problems. there was no difference in the chronograph speeds, report or recoil. substituting small pistol magnum primers boosted the fps up a little but substituting large pistol magnum primers in my .45 super loads bumped up the velocity 50 fps!
I tried to use large rifle primers in my .45 super brass, but the rifle primer cup is a few thousandths deeper and they won't seat flush.