I changed the grips on my 1911 once. When I did I put the screws in pretty tight. Not gorilla tight, but tight enough that when I went to change the grips again a few weeks later, a couple of the grip screw bushings came out. So I had a grip that was off the gun, but it still had the screws through it, with the bushings on the backside acting like nuts on bolts.
Not sure what to do, I consulted the Internet and ended up as carefully as possible using pliers to hold the bushings while I removed the screws. But I still messed up the threads on one of the bushings. And when I tried putting it back in the hole in the frame I cross-threaded it pretty good.
So I bought a set of bushings just to make sure and yep, the hole in the frame was messed up good. It also seemed like the non-stripped holes were a little small. So I bought another set just to make sure I'd not gotten oversize bushings by mistake. Nope. One hole borked and all of them smaller than spec. What I get for buying a cheap 1911 I guess. Oh well.
So I bought a standard bushing tap. I'd never tapped a hole in any material before, much less steel. I tapped all 4 frame holes freehand and ended up with one not quite straight. Actually "pretty darn crooked" is more like it. And it wasn't even the one that I messed up in the first place! Now the other hole on the right-hand side was messed up, and the original messed-up one was still not quite right. It felt like there wasn't much thread material left, and it was about to strip! ARGH!!
So I bought an oversize bushing tap and some oversize bushings. I then made some jigs out of wood (to use for tap guides) that I proceeded to clamp to the sides of the frame. I knew that if I didn't get it right this time then I'd have to have someone weld the frame. I carefully re-tapped all 4 holes with no issue. I then put the oversize bushings in and secured them with red loctite.
The lessons I learned are "be careful", "pay attention", "have the right tool", and "learn to use the tool". I still LOVE the idea of tinkering with my guns, though and I will still do it.
-cls