Have you thought about recontouring the existing barrel?
that is also a possibility
Hart barrels on their web site says they do recontouring of barrels
If you recontour the barrel, you will also have to rework, or replace, the stock. When faced with the same issue that you have over my own 25" Krieger in .300 WM, I had Dixie Precision Rifles flute my barrel. It knocked off 15 oz. and had zero effect on accuracy.
