6 gun accuracy

I picked up a Blackhawk for a song about 20 years ago. It had a bulged barrel from shooting after a squib and really sprayed the bullets. I replaced the barrel with a take off I got on gunbroker and it still shot like hell. I set it aside for a good long while and then decided I needed to work out the problem. I found by shooting groups from only a single chamber that each chamber had decent accuracy but each chamber grouped to a different place on the target. I am not sure if the cylinder was just made horribly or if the squib problem caused the issue. I replaced the cylinder pin and that did not help. I am pretty sure I can get out of it what I put into it, the barrel was only $35 including shipping and doesn't seem to be the problem as the separate chamber accuracy is not an issue. I may have to get rid of it someday as I just don't feel like tinkering with it any more.