Barrel Swap?

i was just on a page and saw something that gave me an idea? i have been wanting a 223 rifle for various reasons. i currently have an axis xp in 308 and axis ii xp in 30-06. can i swap out a 223 barrel for the 308? if so is it a direct replacement or do i need to change anything else? where are some barrel manufacturers who dont break the bank? im not looking for a competition set up. also, would it just be cheaper to get a whole new axis ii in 223? thanks in advance!

Cheaper to buy another gun...