Raimey, You should sight the gun in with the rifle first, then check POI with Brennekes at what ever distance you choose. You may decide to use a different load for general hunting in the rifle barrel so the sighting with it gives a useable POI for the slug. For example, with my Heym's rifle barrel sighted in with 7x57R, 173 gr HMK I can use Brennekes with the same sighting, and with appropriate "hold over" can keep them "in my hat" at 100 meters, which is my self imposed extreme range for Brennekes in that gun. Previous testing showed rifle bullets lighter than 160 gr shoot too wide to allow use of Brennekes with the same sighting as the rifle. Once you are satisfied both barrels shoot together at your chosen range, then you can check group size as suggested by Wolfgang.
Mike
