...haha, ,I must assume that you were kidding... but for clarity, the .500 Smith & Wesson Magnum was developed quite specifically for the X-frame S&W revolver.
There are some words in the handloading business that should be erased from history, stricken from the record and deleted from the vocabulary...
These words include but are not limited to:
--"pistol" and "rifle" and "magnum" when it comes to naming and classifying primers
--Hodgdon "Clays" series of powders... Clays, International Clays and Universal Clays was a horrible naming concept from day one
--I wanna list more but am pressed for time
Both of these merely cause confusion, especially to folks somewhat newer to the handloading scene. Confusion is never helpful in these endeavors.
The .454 Casull round was, if I remember correctly, the first big bore extreme handgun cartridge that actually made the jump from wildcat to mainstream and the .454 Casull had itself a little "growth period" where primer size and type was not yet standardized. We are stuck with terms that say "rifle", "pistol", and "magnum" in primer labels and none of them are helpful. We do NOT specifically use "magnum" primers in "magnum" named loads and it's horribly obvious that we use rifle primers in many handgun applications and apparently, in .50 Beo, we also use the opposite. And if a green and enthusiastic handloader were to accidentally switch up the "Clays" series of powders, he could actually experience a catastrophic failure.
I like to swap brass... and I'm looking for .32 H&R Mag, .327 Fed Mag, .380 Auto and 10mm. If you have some and would like to swap for something else, send me a note!