As OldGringo said the older butler creeks had some issues. They had plastic feed lips in them and I believe called them hot lips if I remember correctly. I've seen some of those that work great and some that didn't, the ones I saw tended to give feeding issues on the last few rounds. Back in the day when there wasn't many options on high capacity magazines, you just had to deal with what you could get. I still see Butler Creek mags for sale, but have no experience with their modern magazines. In my opinion the 10 round ruger magazine is one of them better magazine designs. If its not cracked open or rattling like a baby toy, it shouldn't give you any issues.