Those are some great weights! I got mine on 8/22 also but I don't think one hit 7 lbs. What feed did you use?Got my Cornish X on 8/22 and took them in to be butchered yesterday. They all dressed out between 7 and 8 pounds. I did prefer raising them in late summer/fall rather than spring/summer. They do much better in the cooler temps.
Taking them in, however, was stressful for both them and me. No one in the family will have anything to do with killing them though, so I would have to pay someone to come and help me. I'm not complaing. They are all more than willing to help take care of the chickens.
Around here it's just the opposite...I get no help caring for the birds but do get help with processing.