I got a note from an LEO I know in South Louisiana regarding a problem with his off-duty carry gun.
His issue sidearm is a Glock 17, and if ever there was a place where a plastic pistol is useful, it is the tropics, even if Louisiana is only considered semi-tropical.
When he is off-duty in the summer, he needs something a bit more concealable, and remember, this is a climate where, if you are wearing shorts, sandals, and a T-shirt, you can often be considered overdressed ...
So for a time, he wore a belly pouch with a Glock 26, which is a chopped-down version of his duty gun. Same ammo, same operation, easier to hide. Worked okay, but in some circles, a belly pouch is a give-away that you are carrying a handgun, and he has a bit of a muffin top, so the thing wasn't really comfortable when he was sitting.
Plus he didn't really like Glocks all that much.
Eventually, he did what a lot of concealed-carry people do, he got a small-frame semi-auto and put it into a wallet holder that he stuck into his back pocket.
This is not a wallet that folds, but an open-top holster designed to slip into a pocket to disguise the shape of the pistol while allowing relatively-quick access.
Being a gun-guy, he wanted to personalize the pistol, and so he bought a nice set of custom wood grips and was good to go.
After a few months of carrying this way, he was pleased enough–until he ran into a mechanical problem. One fine day, as he was getting ready to head out, he checked the action, which worked okay, but when he went to eject the magazine, pushing the button didn't work. It unlocked, so he was able to pry the magazine out, but it wouldn't drop on its own.
He got out the Break Free CLP, lubed things.
Still no love.
He had seven rounds, but if he needed to reload, not being able to extract the magazine in a hurry could be bad. And if something was wrong, something else might be wrong.
So he field-stripped the pistol and had a look. Nothing apparent, the mechanism of the release seemed to be working just fine, but the magazine was binding.
He took the grips off, and voila! it worked just fine.
Sometimes, it's the grip screws are too long, but the customs came with shorter ones that seemed to fit right.
After a bit, he puzzled it out: The custom grips he had installed were much thinner than the ones that came with the piece. A selling point in concealment, since they allow for a flatter package. However: In some small-frame pistols, parts of the mechanism in the magazine wells are actually kept in place by the grips. (The tolerances here are not what you'd call precise.)
What had apparently happened was, the pressure of his butt when he sat on the gun had slightly deformed the thin grips so they pressed one of the tie-bars against the magazine, causing it to bind.
Easy fix–he re-installed the old grips, and it worked just fine.
This points at a couple things you need to consider if you carry a concealed handgun. First, realize that changing the configuration of the weapon might do something to its function. Had he carried this gun in a waistband holster or a belly pouch, chances are the thickness of the grips would not have mattered–there'd be much less pressure against the thin wood.
Second, you need to check the operation of your weapon frequently to make sure it is doing what it is supposed to do. Supposedly, Wild Bill Hickok would get up every morning and fire off the whole cylinder load of his old cap 'n' ball revolvers, then reload 'em, to make sure the powder was fresh. The notion was that when you needed to hear bang! you did not want to hear click! which is, I am told, the loudest sound in the world ...