Well, not with my BR hen, Lexie. She and her first baby hatched have VERY wide white bars. The young cockerel's are double the width of two other BR cockerel's I hatched from a friend's flock. Some just dont follow the rules, do they?
Both breeds are very nice, but I do think that Barred Rocks...
The "clear and distinct" lines are not a sure fire way to assess your breed with hatchery birds. For example, the only way I know the hen in the pic below is a badly-barred Barred Rock and not a Cuckoo Marans is her yellow legs (sorry, Ivy, I love ya, but...):
Cuckoo Marans have pinky white legs and Barred Rocks have yellow legs with some black wash down the front, more so on the pullets. That is the most obvious way. Barred Rocks are supposed to have more distinct barring, but with hatchery birds, that is most often not the case.