crowing happens at diffrent ages i have heard chicks try to crow as little as a couple weeks but then my rir roo was 16 weeks when i got rid of him and he never crowed so it is up to the bird when he decised to
i say cockerals too you can also see how light the barred rock is, usually the lighter ones are roos, hope you wanted some roos if not atleast you got yourself a dinner lol