dtabor
I would bet you can salvage that barrel... You would be surprised how well some barrel will shoot even if they have some pitting...
Two things and this is probably the easiest... Contact TC - your gun has a lifetime warranty... they will not replace the barrel as it was consumer neglect... they will however lap the bore for you free of charge (well minus shipping) and they will do a far better job than either I or you if we were to lap it ourselves.
If you want to give a lapping a try - PM Cayugad - he has a lapping procedure already typed up that he can share with you. Everytime I try to write it up I mess it up and leave something out. It is not to difficult just time consuming. Another great resource is Lemoyne...
My choice send it to TC... Call TC and and ask for support and service.