FWIW. Retired police and a firearms instructor for over 20 years. Carried Kimber's for about 6 of those until I got tired of the weight on my skinny hips! This will upset a LOT of people but engineering-wise, any 8 round mag that is the same size as a 1911 7 round mag is going to have issues. I know the Marines use 8 round Wilson's and yada, yada, yada. I'm just speaking from over 20 years of experience and reading a lot about magazine design. There is so much tension in an 8 round 1911 mag that as the rounds above it get stripped out of the mag, they pull the lower ones forward in the mag body. I had a Kimber TLE that using Kimpro mags would do the craziest thing after chambering a round and topping the mag off so I had 9 total rounds in the piece. AFter the pistol fired the 8th round and as the slide traveled back to eject it and the slide was stopped by the recoil spring, the 8th round which had been pulled forward in the mag body by the round above it would jump free from the mag and the mag follower would make it jump out of the gun before the slide could come forward! I had to get someone to watch what was happening and then we figured out what was going on. Crazy! If I loaded 8 rounds and DID NOT TOP THE MAG OFF, it functioned fine. That is why so many 8 round 1911 mags have the raised lip on the top rear of the follower. This ridge catches the 8th round's case rim and tries to keep the round from getting dragged forward to prevent what was happening to my pistol.
The only mag I trusted my life with when I carried a 1911 on duty were Tripp CobraMags. About 15 years ago Virgil Tripp had a video and engineering paper on 1911 mags and explained why it is impossible to make a super reliable 1911 8 round mag based on a 7 round mag body. Unforetunately, that video and engiennering paper is no longer on the website. Tripp Cobra Mags are what he came up with. Virgil discovered that to make a reliable 8 round 1911 mag, you have to lengthen the mag body and use a special floorplate to keep the overall length down. He also makes the mag body walls thinner with better steel. This increase in volume and the extended length allows him to pack in more spring that has less total tension on the 8th round that lessens the chances of that 9th round misfeed. The NRA tested Cobra Mags with a GI spec Rock Island 1911 and the CobraMag feed everything! 185 semi-wad target loads, 200 grain "flying ashtray" rounds, etc. Cobra mags actually hold the round up inside the pistol a few thousandths of an inch to better assure feeding. Check them out. Sorry for being so long. Best of luck. Either load only 8 and don't top off or get some CobraMags. Oh, the Wilson Elite mags are their copy of the CobraMag.
