I have a winchester 1300 12ga and want to use it for occasional trap use. It has a fixed modified choke and I would like an interchangable choke. the barrel had some rust but i got it all off. some minor piting. Is it worth buying a new barrel with removable choke tubes or is it just fine the way it is? Any ideas about how well a 1300 will shoot trap being a feild grade with plain stock and pad?