It is sad that I have to give the mags 4 stars as they are overall great and very gas efficient. The issue is that you will have to file the feed lips as otherwise they WILL CRACK AND BREAK due to how tight they are (3 out of 4 of my original mags have had this issue). To anyone who didn't have this knowledge, they would be out ~$5 to replace the feed lips (each) like me. The mags were shipped out and arrived within 3 weeks of ordering from the U.S., and they were even shipped with a little gas to preserve the seals which was nice!