First: I want my empty mags to drop free, but I do not want my full mags to drop free. If I hit the mag release accidentally, I would rather the mag stay in the gun so I can "Tap" it back in place.
Also, if I do a "Tactical Reload" (replace a partially full mag with a full one while retaining the partially full one) I would prefer to control the extraction of the mag with rounds in it rather than have it jump out from the gun in case I don't get control of it right away.
As luck would have it, Kel-Tec double stack mags seem to fulfill these requirements admirably. They are slightly wider when loaded because of the lateral pressure of the cartridges inside. The fewer the cartridges, the less the pressure. Empty magazines should drop free while loaded ones should pop out about 1/2" (if the slide is closed and pushing down on the loaded rounds compressing the mag spring)--enough to be obvious with a quick look, but ready to come all the way out or go back in at my choice. If the slide is open, a loaded mag should hardly move at all. This is perfection to me.
If I really need to dump a full mag in a hurry, the extra weight of the loaded magazine will accomplish this with just a short, sharp downward jerk of the whole gun while depressing the mag release (slide opened or closed). My loaded mags drop free with this motion.
That being said, most Kel-Tecs need a little help getting empty mags out. I prefer to get my guns this way. Then I can set them up exactly the way I want.
1. Not all mags have the same dimensions. If you are going to adjust the inside of your polymer grip, make sure you are doing so for your carry magazines.
2. I have found the addition of grip sleeves (Hogue Hand-all's, etc.) can slightly distort the shape of the polymer grip of KT's making it harder for the mags to fall free. Squeezing the grip while depressing the mag release helps overcome this. Try this first.
3. The Mecgar magazines KT uses are high quality, consistently sized magazines. It is best to use them with the KT for carry purposes. Fit the inside of your grip to one or more of these rather than other S&W or aftermarket mags. Do inspect them for any burrs or other imperfections that could increase friction, especially at the mag release slots. Wax & polish.
4. All the KT's I have worked on have required the removal of some of the material (especially mold lines) inside the grip in order to get an empty mag to fall free. Unload and completely disassemble the grip from the gun (including the mag release). Carefully file or sand the sides of the grip (inside).
Inside corners may need a little rounding with a small, fine round file.
Test with both loaded and unloaded mags so you can be sure the loaded ones will not fall out, but this needs to be done ultimately with the gun in fully assembled condition.
Note: This article was retrieved from the former KTOG.org Tec Werks section. If you haven't been there, you should give it a shot (get it?)
If you have any other tips to keep those mags dropping free, drop em below.