Back in the 60's Milbro were the only pellets available locally and there were always a couple of deformed ones in the box. We called them "mutants" and shot them anyway.
Makes me think on how, out of ignorance, I fed my FWB 124 whatever pellets were available or on sale and never thought how different brands, styles or weights would affect accuracy.
Now I search for the best pellet for each airgun, quick check each new tin and for special work (sighting in, shooting for best groups and hunting) I'll only use sorted pellets. Casual shooting/plinking is straight from the tin.
Cheers!