Yogi:
I have experimented with shooting large steel ball bearings from automotive CV joints out of a 12-bore shotgun with no chokes, had all the posters over on DoubleGun in stitches for a couple of weeks!

They were convinced I was going to blow myself up!

The test was a failure though, wouldn't hold better than about 4 inches at 25 yds in the final analysis. I might be able to find the link, but I tore down the photos ages ago so no point really. It was fun though!