So far in the years I have been into weapons, I have only had to change 1 mag spring. It was for a factory 15rd beretta mag I picked up at a gun show for $5. Why $5? Because it was a VERY USED MILITARY MAG. The spring was very weak from god only knows how many rds. I had the mag refinished, along with a new spring. I kept the original follower in it. Works great.
"Some People Are Like Slinkies. They're Not Really Good For Anything, But They Bring a Smile To Your Face When Pushed Down The Stairs."