A few weeks ago, I had the chance to chop down a 6" S&W 686 into a 3", which I did by removing the stock tube, unceremoniously lopping it off 'bout thar with an abrasive chop saw, and then rethreading the forward half to fit.
Today we had a chance to test it, and I dragged along a tripod and my digital to snap a couple pics. Unfortunately, with the overcast and the moon above that, it was actually surprisingly light out, even at 8:00pm. So I had to drop the ISO and close the aperature down a bit, because I had to use the timer to make a long exposure. But still, I thought it came out nicely:
For the gun nuts, the load was a .357 CCI Blazer with a 158-grain jacketed hollowpoint, fired through a S&W M686-3 with a 3" barrel. For the camera geeks, this was a 15 second exposure at ISO 100, taken through a Canon 50mm f1.4 set at f2.8 on a Canon 1DMkIIn digital shooting large JPEG.