Hi everyone,
I saw a post on Reddit where a guy cut down the follower on a Mecgar 19 mag, and decided to give it a try.
I used a hacksaw blade to initially cut the follower down, then used sandpaper to take it slowly and evenly down, cleaning up the edges with a sharp knife.
When I could load 21 (with some effort) I stopped, and had to chamfer the lower left edge of the follower so it wouldn't hang up on the mag catch window loading the 5th round (2nd picture).
The slide locks on empty and I have about 100 rounds through it, most shot in a match. So far, so good.
If it works well for a few hundred more rounds I'll do the same to a couple of other identical mags.