Excellent thought, coosa. I think you re right about it being impossible to have a S x S that is perfectly regulated with all loads, especially turkey loads like you're using. They can be regulated for the majority of field loads, however.
I totally agree that regulation can't be determined by the price you pay for a gun. My little Yildiz Elegante 4's regulation is as perfect as anybody can ask for, with anything from 1/2 oz. to 11/16 oz. loads ............... and it was on sale NIB for $400 about five years ago.
I'd offer what I mentioned back in a previous post on this thread, that most of my vintage S x S guns have been nicely regulated, and I've never patterned a Fox that wasn't. Your issue is that you're probably trying to get them to regulate with very heavy turkey loads, and few, if any, are built to do that.
Thanks, SRH