Thanks Coosa,
What you have written it similar to my thinking.
What options do you have if you have used some method to shift the point of impact and now have a problem pattern? What then can be done to correct the pattern?
Well, I am no gunsmith, just someone who has tinkered with a few guns to try to make them usable. The only thing I have done is to remove the choke tube and start over with a new one. I have several chokes that were filed and I was unhappy with pattern so they are just discarded.
I would do this on a fixed choke gun only as a last resort. I have a cheap Spanish gun that I have mentioned before on here. It cross fired so badly that you could put a can 30 yds away and wouldn't touch it with either barrel. The left barrel would put every pellet to the right of the target, and the right barrel would put every pellet to the left. It was made in the 60s and still looked new when I got it. I suspect that more than one owner got very frustrated with it.
There was nothing to lose by filing it. I found that it didn't take much filing at all to center my heavy turkey loads, and the patterns were still pretty good. Now note that while it now centers a 1.625 oz tss, it will still cross fire field loads. Still, I enjoyed taking a very flawed gun and making it useful. It's my backup turkey gun and has taken a few birds over the years. The Yildiz throws a better pattern so it is my primary gun.
I realize that it would be foolish to attempt this on a quality gun with fixed chokes. But on a cheap guns like this one, trying to fix it yourself is a reasonable option. Sending it to Stan's gunsmith to regulate the barrels would likely cost more than the gun is worth.
