Years ago only Savage had nutted barrels that could be easily changed out. Over the years barrel suppliers have made prefit nutted barrels available for a number of actions.
Northland Shooters Supply does Savage and Rem, I've ordered a few
Shaw barrels makes them, I've put on a couple
Urbanrifleman does Savage, Tikka, Ruger, Howa, Winchester I have one of his 223AI barrel his are mainly heavy target/varmint withe smallest barrel a .750" muzzle
I've had PacNor install a barrel and make a prefit for me good people
X-calliber does barrels, I have 20P by them and I believe Reb600 won the egg shoot with one of their barrels.
McGowen, EA Brown band a number of others supply barrels