I've inherited a 22 MRF ctg pistol and would like to fire the weapon but I'm unsure of the type of ammunition. I'm getting differing information as to whether I can use WMR ammunition which is easy to find or if I have to use MRF ammunition. The WMR ammo will chamber just fine, I'm just a bit afraid to fire it because some sites say it may create an overpressure situation. As you can probably tell I don't know much about these firearms. Any information will be greatly appreciated. Thanks