[Model12]

I recently picked up a Combat Commander (with orig mag) that had a "lock open" failure, as in it would not lock open. One night while piddling, I removed the mag follower and put it next to another Colt mag follower, and sure enough, the profiles were slightly off from each other. For whatever reason the defective CC follower had yielded or been forcibly bent "down" and was not actively engaging the slide stop.

Using the "good" follower as a template, I simply bent the CC's follower to match. All is good now. Of course, if the follower has a weak material issue, it may yield again.

As to the tight safety...I can't comment on that.