They are all versions of red sexlinks, which isn't a breed but a cross breeding for the specific purpose of sexing chicks accurately at hatch, by color. Each hatchery has it's own 'brand' name. The breed of rooster used is usually a Rhode Island Red, New Hampshire, or Production Red. Hens are usually Delaware, Rhode Island White, White Rock, or Light Sussex.
But you can produce red sexlinks using just about any red-base color rooster with any silver (black and white) hen.
I don't know if they are exactly the same, but they are all hybrids bred with the same goals in minde,sex-link, fast growth, early POL, high egg production in the first year, calm enought for big flocks and hardy enough for a free range. Like most commercial hybirds they make great pets and the egg production is good enough for a secound or third year for most backyard owners. They normally don't live as long as the old landraces but with a little luck you will have happy hens for many years.
Great info, thanks.
I recently bought 10 moulting hens, supposedly RIR. It was a mercy case really, as the guy was out of money and out of food for them - and it was freezing cold, poor bedraggled things. These so called RIR's are definitely red sex links of some variety, which isn't really a problem for me, though I would have preferred some heritage breeds. Like I say, they needed help fast and I have the room. One thing I've noticed is that they eat a lot!!! Their little snubbed beaks are never far from the feeder, unlike my original 'farm house specials' who are more content to sunbathe and peck around the yard. The newbies are also laying quite well, too, which surprises me immensely considering how moth eaten they look.