A red dot type optical sight is excellent for turkey but if used on deer,you'll need the precision ofthe smaller dot models so choose accordingly. One thing to remember is the center of your pattern (aiming point),MAY NOT coincide with your slug barrel's sight in point of impact. Another thing to remember is anytime you change barrels,ALWAYS check to ensure it's still sighted in as they can change point of impact due to tolerences (slop or play) between the barrel and action. Having said that,go with a 4-5 moa dot and you should be fine.