I agree with Wildwilderness. But, if you are serious about boring out the barrel, research gunsmiths in your area or region of the country who does the work you want. Then, ask if your barrel diameter at the muzzle can even be used, and the cost for the work and shipping if required. If the 'smith will only return the work to an FFL, there can be an additional cost as well. If you decide to re-barrel, there are custom barrel manufacturers like the one Wilderness recommended, ER Shaw and more, that are not that expensive. Price compare both options, consider the pros and cons, then you can make an informed decision.