No, hatcheries are a horrible source if you want to breed to SOP. They have to have the genetics to begin with and hatchery birds simply do not. They are mixed with Leghorns and lordy knows what else to make them great egg laying machines. For example, I got what was supposed to be a great dual purpose bird, the buff orpington, that is supposed to grow to 6-8 lbs if it's a pullet. None of those full grown hens are more than 4 lbs. No matter how many years I breed them, they'll never be twice their current weight. Oh sure, they lay ok. But in fact, they don't really lay any better then the ones I got from a breeder that indeed are 6-8 lbs
Edit: And before you say "mine are that big", wiegh them. You'll be surprised at how small they really are under those fluffy feathers.