We spend a lot of money and time on the firearms that we carry, however magazines are a big consideration as well. There are a few things that should be addressed about magazines; the first I would like to discuss is the myth about a fully loaded magazine wearing out the spring. Magazines from a few decades ago did have some spring problems and leaving a magazine fully loaded could potentially wear a spring out, however in recent years the technology for magazine springs has substantially improved. In modern firearms it is not an issue to leave a magazine fully loaded and this will not wear out the spring. What does wear magazine springs out is constant loading and unloading of the magazines so if you are firing a ton you may have to replace the springs down the road. Another issue to talk about is when and how often to clean magazines. I typically suggest pulling the magazine apart and cleaning them about once every six months, especially if it is a firearm you are carrying on a regular basis. Firearms that we are carrying a lot tend to attract a lot of dust and lint and this can affect reliability if it builds up enough. It is advisable to leave the magazines dry when you are done, if you leave lubricant in the magazines it can negatively affect the ammo that goes back into it. It is perfectly fine to put a little life back in the springs as well, however, don’t over-stretch the springs as this will negatively affect reliability as well.
There are some modifications that can be done to magazines such as magazine extensions or wider base plates; however they need to be done properly to avoid feeding issues. Most large magazine extensions will come with a larger spring to accommodate for the extension, while some smaller extensions like a plus one can utilize the factory spring in some cases. It is always advisable to go out and function test any modification before carrying it for personal protection. I usually recommend that you test fire with the magazine full to start, then load two or three rounds and ensure that they feed properly. I typically do this four or five times before I carry that particular magazine with my personal protection firearm.