What I am looking an looking for is something that has a double breast and a fairly fast growth rate. It doesn’t have to be 7-8 weeks. Just a bird I can dress out and have 5-7 lb of meat. I’m not sure what the Cornish x are when they are butchered.
I don't think you are, but if you are willing to buy chicks each time you cannot beat the Cornish X. You just can't. But it is extremely challenging to keep them alive long enough to breed. And they are hybrids. You know what happens when you cross hybrids, you do not get consistent offspring. They will have genetics for fast efficient growth so even the worst should be better than most dual purpose bird but some will be better than others. The hybrid part doesn't worry me that much as they still all have good genetics for fast growth. It does bother some people. It takes so much effort to keep them alive to breeding age that it's just more efficient to buy chicks.
I'm not that into turkeys but the most efficient at putting on meat are the Broad Breasted, maybe the Broad Breasted White. One problem with them is that they get so big they often cannot breed, you may need to look at artificial insemination. I think they develop health problems as they get older too, somewhat like the Cornish X. I've raised a Midget White, much smaller "heritage" breed and not as efficient but easier to keep alive. Probably not what you are looking for but maybe. You can breed them. They fly really well.
I have not raised Rangers so I don't know how hard they are to keep alive. They may be closer to what you are looking for.
I have a fair amount of knowledge in selective breeding as I have breed genetic hackle birds for a decade.
Good, then you will probably be able to follow this. Some meat bird breeders use dwarfism as a trait to reduce feeding costs and make it more efficient in managing the parent flocks of the meat birds. I don't know if any of the Cornish X strains have it or not, I have not heard that they do. But I have heard that some of the Ranger strains use it. Dwarfism is a recessive sex linked trait that reduces the size of the bird. You can see that that makes feeding them less expensive and reduces housing requirements.
Without getting into more details if you use a Ranger hen in your breeding program you will not bring dwarfism in. If you use a Ranger male there is a chance you will. Somebody, probably
@nicalandia had some information on which Rangers that was.
I could raise a few groups to meet my meat goals. I have an incubator that can handle a lot of eggs. If they will be 4 lbs of meat I’d take that if that’s a middle ground as to what to expect. I could raise 2 groups of 50-75 and make my meat goals.
I was going to ask this, how much meat do you think you'll need. I only hatch 40 to 45 chicks a year. I can get two meals out of a pullet so size isn't that critical to me and with visiting grandkids and other activities we don't eat chick every week. A nice big cockerel just means I get chicken for lunch. Mine forage for a lot of what they eat, it sounds like you may be planning on providing most of what they eat, either buying it or growing it. Different factors to consider. Since yours is a "weight of meat" goal I think you've already hit on the idea of maybe raising more as opposed to just going for the biggest individual.
It sounds like you already have the facilities to brood large amounts of chicks. Do you have the freezer space to store that much meat if you butcher that many at the same time? Do you have the time to butcher that many at a time?
In reality I haven’t ever raised birdd for meat. Just feathers so I don’t know how much meat to expect.
Do you skin those birds for their feathers? I so, what do you do with all that meat? Do you use both girls and boys feathers? I know those birds don't have a lot of meat on them but people eat tiny quail. Those birds are probably pretty old so you would have to be careful how you cook the meat but the French developed Coq Au Vin to make a gourmet meal out of an old rooster. Chicken and Dumplings is a comfort food made from old hens. Some people make sausage from old chicken's meat. You could use that meat to make chicken salad, tacos, or soup if you cook it right. Not sure if you have a potential source there.
If you have never raised birds for meat, I would suggest you raise a few each of several types, and experiment with butchering them at several different ages. Doing that once will teach you a lot about what is important to you. Then you will be able to make better decisions about what to do next.
As far as I'm concerned this is some of the best advice given on this thread. Trial and error and learning by doing not only shows what works best for you but what is important to you. What I did changed after some trial and error and I grew up with chickens.
Keep asking questions and formulate a plan. Probably a few plans. Then invest some time and effort to gain that experience. See for yourself what works best. You may find that buying Cornish X chicks (or Rangers) is so much simpler than trying to keep a breeding flock that that is how you want to go. It's a yearlong commitment to keep a breeding flock and you have to feed them. To reduce the number of chickens in your breeding flock or if freezer space is an issue you might have more hatches at different times in the year instead of a couple of big hatches. Be flexible.