Your best bet is to look for a used factory barrel on eBay. As long as you insure that it is a Hawken barrel, and not a Renegade, it will drop right in. Thompson Center used 15/16 inch barrels for both 45 and 50 caliber Hawkens. Depending on the condition, you're looking at $75+ for a beater, up to $200 for one in brand new condition.