Your cold bore shots will be somewhat off from your fouled barrel shots. When I am training with my sniper teams, we record our cold bore shot first, and then shoot a group. Here's what I would recommend for you. Shoot a round or two before making any scope adjustments. After your scope is zeroed, clean your bore while in the field or on the range. Then, fire one or two rounds, and put the rifle away until your next hunt or range visit. This will leave you with a "lightly" fouled barrel that will give you a cold bore shot well within reason of your scopes zero, but will not be harmful to your bore.
Active LE Sniper, AR15/M16 Armorer, Firearms Instructor, NRA Certified Instructor, Taser Instructor, Sniper Team Leader, and owner of www.bigrivertactical.com