I think you might need to find some faster growing birds and see if crossing them into the meat birds will result in better birds. You might end up with smaller though. I raised a Brahma rooster and he took a long time to grow out, was going to keep him for breeding until he turned into a jerk. I think he was about 8 months when I butchered but he was big. Brahmas are slow growing.No, I am only interested in self sustaining flocks. I went with Standard Cornish figuring more breast. Maybe I got small birds from a hatchery? But the roosters look good and the hens are a bit small at 20 weeks from what I was expecting. Maybe I should have bought a few from a heritage breeder? But I don't know of any near me.
The Brahma/RIR crosses my daughter raised are every bit as heavy as my largest Cornish Hen. I was considering starting over with something else and was hoping someone else was on here with heritage meat birds.
My wife is getting attached to anything we raise now. I have to lock up "eaters" somewhere she can't see them, or she can't eat them. I made chicken soup from an Azzhat rooster she wanted dead and she wouldn't touch it. Because it was "Bigman". I said "Stop naming your food and it wouldn't be a problem."