My Butler Creek Steel Lip has gotten five or six failures to feed. I noticed when loading that sometimes, after pushing a round in, it takes a bit of a shake to get it up. I'm guessing this was happening in the gun, preventing the next round from getting up to where it can be scooped out. I'll qualify this by saying that it was a pretty chilly day, it was the first time trying the mag, and of the three or four times I loaded it up, it got better each time. I've yet to get my hands on more mags to test them though.
Something I'd consider is BC's mag loader. Mine missfed the one time I tried it, not always loading the round. I've yet to trouble shoot it, mostly because my 10/22 is getting new sights, and it doesn't make sense to unload the magazine just to load it again. I plan on reporting on it when I can though. It seemed to work well with the rotary mags too.