You have to really watch size when choosing your breeder birds. Look for breeders 1.0-1.3 pounds with big round heads, tiny bills, tiny feet, short round bodies. These will lay well & should produce some of the smaller show quality size birds of 10-14 ounce size but will also produce some birds over the 1.5 pound mark. These mid-size birds make the brest breeders because they are heartier & lay better than the tiny show quality birds but will still produce those tiny show birds.
My little drake weighs in at 1.06 pounds. All but 1 henn fall in the 1.2-1.4 range. My tri-colir hen weighs in at 1.9 pounds. She will be culled (sold as a pet) later this summer. I am trying to get a smaller baby from her in her color first.