My experiences lead me to believe that the chance a random barrel will fit a single receiver without modification is low. That is why if you can afford it, you increase your odds dramatically by owning multiple receivers. I keep the ones that are slightly different size wise from any others I have. I will say this though, I have had about 10 Handi rifles made on the CBA frames and for some reason, perhaps coincidence, the barrels seem to swap well between them. Perhaps H&R has made some improvements in this area, I don't know.