I tried PRBs in mine fisher1, and could not get what I considered acceptable 50-yard accuracy. I tried loads of GOEX FFFg from 25 to 50 grains.

However, as you can see from the target below I did find a sweet shooting light target & small game load with sabots and 125 grain jacketed bullets. It was very finicky finding that load though. Five grains more or five grains less opened the groups up considerably.