JCP
Yes, it appears that you have need of Ruger's services. It's too bad. I've had incredibly good luck with every fixed sighted revolver I've ever owned. Some I've had to "tweak" a bit, but never more than a couple inches at 25 yards. I absolutely hate Kentucky windage!
Fixed sighted revolvers are not for people who don't feel they have the necessary tools/skills to make the corrections. I'm a tinkerer. I like fixed sighted revolvers because I'm not much into experimentation. When the load is right, that's the load I use and having a gun regulated for that load suits me.
Others, who may want to try different ammo/loads, really should stick with adjustable sights.
I hope you get it worked out. While the Blackhawk is a lovely revolver, there is something that it lacks from a purist's perspective. The best revolver Ruger ever made was the original "Blackhawk" flattop in .357! It was nearly absolutely perfect in balance and yes...it had adjustable sights. But it would have been just as good had they simply used a drift adjustable rear sight.
Regards
Dan