About all I could suggest is a custom barrel. Perhaps Green Mountain Barrel could help you out. They do have a barrel I believe is 1-24 and made to shoot conicals in one of their custom Hawkins but you have to purchase the barrel, rifle and a tube scope. Whether they would sell just the barrel I do not know. I heard they will not just sell the barrel.

http://www.gmriflebarrel.com/productdetail.aspx?id=920160S