Treading lightly around the retired armorer, I beg to offer a bit of additional information. It has been well established that 1911 mags AS DESIGNED, can stand being loaded for many years. There is a new problem, however, the short follower, allowing 8 rounds to be loaded in the mag.
Further, I change the recoil springs on my 1911's regularly. At about $7, I think that they are cheap insurance.
Here is what Wolff Gunsprings has to say:
4. How often should I change my springs?
Wolff Gunsprings are made with the highest grade materials and workmanship. Most Wolff [recoil] springs will remain stable for many thousands of rounds. The performance of your gun is the best indicator of when a spring needs to be replaced. Factors such as increasing ejection distance, improper ejection and/or breaching, lighter hammer indents on primers, misfires, poor cartridge feeding from magazines, frequent jams, stove pipes and other malfunctions are all possible indications of fatigued springs or improper springs. Springs that are subject to higher stress applications such as magazine springs, striker springs and recoil springs will require more frequent replacement than other less stressed springs. Most Wolff recoil springs should be capable of 3000-5000 rounds minimum before changing is required. Some recoil springs in compact pistols, especially where dual springs are replaced by a single spring may require changing after 750 - 1500 rounds. Changes in your firearm's performance are one of the best indicators that a change is needed.
5. Should I unload my magazines, rotate magazines, load with fewer than the maximum rounds? How often should I change magazine springs?
Magazine springs in semi-auto pistols are one of the most critical springs and the subject of much debate and concern. Magazines which are kept fully loaded for long periods of time, such as law enforcement applications, will generally be subject to more fatigue than the weekend shooter's magazine springs which are loaded up only when shooting. Magazine design and capacity also affect the longevity of the spring. Older designs where maximum capacity was not the goal such as the 7 round 1911 Colt magazines will last for years fully loaded. There was a lot of room for a lot of spring which reduced the overall stress on the spring. In recent hi-capacity magazines, the magazines were designed to hold more rounds with less spring material. This puts more stress on the spring and will cause fatigue at a faster rate. Unloading these magazines a round or two will help the life of the spring. Rotating fully loaded magazines will also help the problem somewhat but is not always practical. In applications where the magazine must be kept loaded, a high quality magazine spring such as Wolff extra power magazine springs, will provide maximum life. Regular shooting will verify reliability and regular replacement of magazine springs will provide the best defense against failure from weak magazine springs
So, it seems that occasional changing of the recoil spring is accepted procedure, and leaving a 8 rd. 1911 mag fully loaded with a regular strength mag spring in it might not be a good idea.
Respectfully submitted, Walt Welch