I have a .31 Colt Pocket pistol that I'm having issues with loading. The ball has a tendency to slip back out past the front of the cylinder causing the cylinder to jam. Near as I can tell from making a few measurements with calipers, the mouth of each chamber is .003 to .004 smaller than the inside diameter. I'm thinking chamfering the mouth would resolve the problem. I know there are tools for some various caliber cylinders but I'm not finding anything for any of the common BP pistols sizes let alone a .31. If anyone knows a source for such a tool or can suggest another method, I'd like to hear about it.