Never shot a .25 to be honest. Last time I went seriously ratting was on a mates farm back in the '70's, think a Diana 27 .22 c. early '50's was the tool then.
Forgive my ignorance - at 7 yards wouldn't open sights be just as easy, rather than a scope? Not being funny, just curious.
My only recent experience of rats is finishing off damaged ones my feral ex farm cat used to bring back, when I lived in Malvern. Saw more rats there than I ever do out in the village.

ATB

Bru