Quote Originally Posted by STAMarine View Post

I also don't have any info for preventive maintenance for 9mm 1911s such as a schedule to change springs, or even spring weight for it. Does anyone have this info?
Recoil spring according to Bill Wilson:

Most 1911 9mm caliber pistols will function properly with a recoil spring in the 11# – 13# range if a tight/firm grip and proper ammunition is used. Conventional music wire recoil springs should be replaced every 3,000 rounds, chrome silicone round wire springs every 20,000, rounds and chrome silicone flat wire springs every 40,000 rounds. Ideally you want to run the heaviest recoil spring that will function properly with the lightest ammunition you plan to shoot. To check for spring weight/ammunition compatibility, go to the range and load a single round in the chamber using a magazine proven to reliably lock the slide open on the last shot fired. Fire the shot weak hand only, and if you can do this with reliable slide lock operation 10 consecutive times your recoil spring is not too heavy for your ammunition. Ideally you want the heaviest recoil spring that will pass this simple test because, the heavier the spring, the more positive the feeding of cartridges from the magazine to chamber.

https://www.wilsoncombat.com/faqs/