I was to keep a Magazine ready by keeping it full, will this damage the Magazine spring, where the gun will not load?
That's exactly my understanding as well. I had a Gen 2 G21 for 18 years and I had exactly 2 magazine for it for all those years. I probably put about 5000 rounds total through it and when it wasn't in use, those mags were full loaded all the time, for 18 years. I think I went 3 years without shooting it at one point. Those magazines never had an issue after 18 years, like new.Nope. Springs wear out from compression cycles, not from being under constant load. The interwebz taught me that. Your feed lips will bend before the spring is damaged.