Anecdotal information can extremely misleading without certifiable backup data. It could be whoever spoke this information really didn't know what they were talking about for a multitude of reasons. We see this frequently when someone wants to appear to be an expert and they aren't.
Like any other bullet though, there is always the possibility that the barrel simply isn't compatible with those bullets. Maybe they had the wrong twist rate?
I've shot both of the Bergers with superb accuracy in 4 different cartridges and 4 different barrels all same manufacturer. I may be the exception but I doubt it since I know lots of other .25 caliber shooters who have reported the same accuracy.
Enjoy the process!