Just a fun pistol. Better with BBs but will fire pellets; better if you pass them through the barrel first!
I have an original boxed Diana model from about 50 years ago .... I had it from new, Xmas present. Great fun shooting from the upstairs landing into my room at paper targets in a box stuffed with old rags; must have been all of 10 feet. Then I retrieved the BBs or pellets to use again.
Cheers, Phil