When I was stocking gun store shelves, one type of item I tried to make sure to keep in inventory was gunsmithing tools: files, stones, and yes, even Dremels.
"But Tam," I'd hear, "there's a gunsmithing department out back! Why are you stocking that stuff?"
Exactly. And there's nothing like an overconfident DIY'er to keep them busy, too.
There are a hundred and eleventy ways to booger up your gun unless you know exactly what you are doing. While light primer strikes caused by backing out the strain screw on your S&W revolver to "make the trigger pull smoother" are fairly easily remedied, it can cost a lot of money to find out that it's hard to put metal back that shouldn't have been taken away in the first place.
Now, I like gunsmiths. A lot of my friends are gunsmiths. I don't want them to starve. But I think that they wouldn't mind me reminding folks to be sure and know what they're doing before they try and take metal away.
Besides, it's not like anyone listens, anyway. ;)