the magazine spring and ruin it?

I know you can't take the mags apart and replace the spring.

Thanks

CRC

No.  It's the constant flexing and unflexing that causes metal fatigue.

No.

I agree with Vinnie.

Thanks

CRC

NO, it is the constant loading and unloading that will weaken the mag.

On postban 10rd cripplemags, more likely than not it will weaken somewhat.

See, postban 10rd cripplemags must be made such that not even a single extra round can be inserted, by law. This means they must make the magazine in such a way that there is absolutely no room left for the magazine spring to prevent overcompression of the spring. On preban mags, you will notice that many will just barely accept an extra round. That room was for the magazine springs; crushing them down flat isn't good, so they leave a bit of space for them. No such space is permitted on postbans.

However, I wouldn't worry about it too much. Repeatedly flexing springs causes more fatigue than leaving it in one position. It's just that a postban spring will weaken sooner than a preban because it is being compressed *more*, whether it is sitting still or being used.

Check on them more often and they should be ok. I would rather use preban magazines for any life-or-death situations, if available, because they would be designed to work, not to comply with some kind of law.