I got my brass drift out last night and took a close look at it. The end I hit with the hammer was flared out pretty bad, but I already knew that. What I didn't notice before was that the tapered end was peened out a little bit too. So I chucked it in one of my cordless drills and used the fine wheel of my bench grinder on the top end, with the drill turning the opposite direction of the grinding wheel. I swapped ends in the drill and spun the taper against a flat file until I was happy with the shape. And I spun both ends against some sandpaper in my hand to smooth it out, then spun the very ends against a piece of sandpaper lying flat on my workbench. I didn't bother shining it up so it doesn't look new, but works like new. And it's known by the state of California to cause cancer, but then again, EVERYTHING is known by the state of California to cause cancer. They even had a Prop. 65 warning label on some ramen soup I bought this summer.

I hope I don't die from eating, or from working on my guns. It's easier to get measurements on my brass punch now and it's 5/16" x 4 1/4" x 3/16", like I thought it was.