Callaway uniflex shafts | Golf Monthly

They are definitely a one size fits 80% attempt at a universal shaft to keep their costs down. I don't think anyone would try and get away with that one these days. The simple law of averages would mean that it would just be hit and miss as to whether these suited but it sounds like you are having major dispersion problems with them anyway. I think the sooner you go and get tested for some other irons shafts the better.

Depending on how much you want to spend changing them over, have a look at FST (who have a good range and make the KBS shafts) and Apollo shafts. Very well made shafts for their price point.