I ran a 50 round box of the Inceptor Spory Utility (standard pressure, not +P) 65 grain ammo through my R51. It worked with no problems at all. Felt recoil was lighter than standard weight ammo.
The Inceptor ARX 65 grain defense ammo (standard pressure) also worked fine.
This type of ammo is a potential solution for guns that are finicky with hollow points. My original reason for considering this ammo was for a 380 that has issues with hollow points. Then I was just curious how the R51 would handle this type of ammo.