Possibly so that they can sell you another clinder?? Am I being too cynical?
It's an age-old practice to shoot .38 specials through a .357 or .44 specials through your .44 mag. Same thing applies to the .475 and .480. Just make sure you clean it well afterwards.


Max Prasac

Semper Fidelis

BIG IRON: https://www.youtube.com/watch?v=L6aXjMH5C30

Gun Digest TV's Modern Shooter: https://www.youtube.com/watch?v=nGo-KMpXPpA&t=7s