Chick sexing... help!

[EnesaMac]

I have 5 4 week old chicks that I would love help sexing
Buff Orpington
Silkie
Plymouth rock
Australorp
Araucana
Thanks

 

[Silkie Princess]

Still too young to sex but the Silkie's comb looks big

 

[3KillerBs]

I can't say for the others, but I'd have expected any single-combed boys to have a good start on a comb -- still, they're way too young to be sure (I had a Blue Australorp girl pop some comb at 3 weeks, get banded as a potential boy, and be clearly female at 12 weeks).

 

[CaliFarmsAR]

Do you have any update pictures?