Quote Originally Posted by ellobo View Post
There are a lot of little nuances you have to pay attention to when swspping barrels, like proper setting of headspace, possible magazine changes (what magazine do you have/ Stagger feed, center feed, DBm?) Bolt head may have toi be changed out. You should get a good aftermarket recoil lug. Will the new barrel be free floated in the stock as well as the tang? All depends on what you are changing from-to. None of this is hard to do and how-to is available here.
Welcome to the brotherhood of the barrel nut. You are now officialy a "NUT".

El obo
The OP sounds like he is thinking about the most straight-forward caliber change imaginable, a .308W to a .243W. Both use the same action length, same magazine, same bolt head and even the same headspace gauge. About the only problem might be if he chooses a barrel with a significantly different contour and has to modify the stock's barrel channel.