bull barrel

Are kimber actions any good? Is there possibilities of putting different stocks on kimbers? I've read something about the action or stock not being able to handle a heavy barrel well. Looking for insight

If you already have a Ruger 10/22 Target with bull barrel, is there any improvement to buy an aftermarket bull barrel for this rifle? If yes, what aftermarket bull barrel brand/model would be a accuracy improvement for this rifle? Thanks.