For sighting in swab the bore after each shot get it shooting groups,then adjust the sights. After getting it zeroed where you want ,clean the bore for the next shot,THEN shoot it and watch the accuracy drop off,or how many shot you can take and still hit in the group. This will be your effective load range. It may be 2 shots,or as high as 5 shots,but clean it out each shot until you have it hitting where you want. Then go for the marathon!