I processed my rangers at 12 weeks. For weeks eight, nine, and ten we had a horrible heat wave, temps near 100, humidity high. Not normal for upstate NY! My poor rangers ate very little, spent all day with wings out from bodies, beaks open, panting. Only ate morning and evening for those three weeks. Still, when I processed them, we had a few at 5 to 5 1/2 lbs, several between six and seven pounds, and a fair number from seven to seven and three quarters pounds. I shudder to think how big they'd have been if they'd been eating for those three weeks!
though they had an outdoor run, they did not free range. I fed them starter, then a mix of starter/grower and grower/finisher to achieve a lower protein as suggested by JM Hatchery. I had one that had to be separated to grow out because of leg problems. Another had some trouble but outgrew it. I started with 31, lost none. I was very happy with these birds. They're beautiful, active, great personalities, and they were big and meaty. I was sorry to see them go.