I have to agree that this must be the case ... especially the older style.
I've had loads of HW barrels that have all been good re air rifle pellets. Same with Falcon barrels which I believe are Lothar Walther and the CZ barrel on my S200 is very accurate.
I've had a few BSA 0.177 barrels and they are basically useless unless you use longer heavier pellets like Bis Mags, JSB Heavies etc.
Whenever there's a thread about BSA barrels ( rifles ) plenty people agree with that but several others will post and say their BSA barrel is excellent with the more popular, and lighter, JSB 8.44gr pellets.
So it seems it's a lottery.
A number of people figured that the BSA method left imperfections in the rifling and that was improved by polishing. Post polishing the accuracy improved.
The later BSA barrels are apparently polished post production and more people have claimed that they shoot the lighter stuff well.
Pushing pellets down my BSA barrels has shown a big variation in tight/slack areas.
https://www.youtube.com/watch?v=bnnBoann6CY