Kitchen Table gunsmithing is a term sometimes used by those who tinker with their firearms, butter knife and Dremel Tool in hand, because they’re either too cheap to go to a trained person, or they, based on their years of experience, think they know better.
In my years as a shooter, gun owner and trainer, I’ve encountered a few of these folks, and their accomplishments, to wit:
The guy who decided to install his own ambidextrous safety on a 1911, because he’d taken another one apart and saw how (he thought) it was done.
Fortunately, he was bright enough to test-fire his work. It doubled and tripled. While I’m pretty sure, that fire control may have it’s advantage in a sidearm, I’m sure the BATFE would disapprove without the proper form. (He did have a professional correct his work to semi-auto.)
Another guy-a reserve deputy sheriff-purchased a S&W model 64, .38 Special for duty use. A fine weapon. His kitchen table gunsmith (aka his barber!) drilled out the cylinder to accept .357 cartridges.
I actually observed him firing this thing at night, and between the too-wide flash gap and the magnum cartridges, it was quite a show. I’m guessing the .38 pressure-rated frame stretched a bit due to the hot loads. He always referred to this gun as ‘my Magnum’. (I think he had other issues.) I lost touch with him, hopefully he didn’t lose a hand or an eye.
I had a slight touch of this disease, myself. I attempted to remove some pistol stock screws with a standard flat-bladed screwdriver. Chewed the crap out of the screw heads. I now have a set of proper gunsmithing screwdrivers!
As Inspector Callahan said, “Man’s got to know his limitations.”