[drail]

With an empty gun lock the slide open and look down into the magwell and see how much engagement you have (or not) between the follower and the slide stop's lug. Manufacturing tolerances can vary between the people who make the guns and the people who make the magazines to the point where the slide stop cannot reach the follower. On some magazines the follower can be "adjusted" (bent) enough to make it reach. It sounds like your followers have a lot of "wiggle room" inside the mag. Personally I wouldn't sweat it too much. All of my pistols have been modified NOT to ever lock open on empty because I have seen too many instances where a pistol that locks open on empty will also lock open halfway through a magazine. I have learned to count the shots and never shoot the gun dry. This is how most IPSC competitors do it. (probably not legal for IDPA) If your not having any failures to feed the last round with any magazines then your mag springs are OK. As soon as any last round feed problems show up than your mag spring is toast. On high cap double stack mags I would download the mag by 2 or 3 rounds IF you're going to leave it loaded full time. And if your mag springs are 3 years old they're most likely shot by now (especially if they have been loaded to full capacity most of their life.)