You're not asking the right question. What's 'best' for your gun for sighting in may very well not represent the accuracy you'd get with your 'hunting' slug in the field. You should sight in with the shell brand/type/weight (Brenneke, Foster, Sabot, etc.) that you will use for hunting. Spend the extra few dollars instead of being disappointed in the field. Suggest you take a look at this: http://www.theboxotruth.com/docs/bot46.htm