I was experiencing different problems with each mag even after I fixed the extractor problem the gun was having. When I pulled the springs, no two were the same. Different numbers of coils and lengths. One was a TripleK 9 round(came with the gun), and the other two are surplus Star marked 8 rounders. Now I can load all three to capacity and have no feeding issues. The mag bodies were all out of shape, too. I worked each one while checking progress with calipers until they seated easily, and dropped free. The TripleK was way out of square when I began. I like having the additional round, and it works as well as the Star mags. TripleK's pricing on new Model B mags is a little high, and the quality is hit or miss.Guitarman, In past years I built at least fifty pistols on Essex frames, each required careful fitting of rails but all functioned just great. I have never replaced springs in my magazines, must have 25-30 of them counting those in pistols only problems I ever had were from a few Triple k mags that made it into the pile. In all fairness I have four other Triple K model B mags that are doing just fine.
The mags that were included with my 1911 were the same way when I got it. Each required some messaging to get them seating easily and dropping free. Springs were fine. Bought a couple of Mec-Gar 1911 mags which are very good, IMO. No issues with them in my range testing.
Anyone shooting these old guns, should treat the mags with care. If you are going to drop them to the ground, put something to pad the impact so they do not take on damage. I cannot be sure how any of the mags mentioned above got so out of shape, but I lean towards them being allowed to drop onto hard surfaces while training. Over time, they could become more difficult to use or worse.