Get front and rear sights that mount on the vent rib like some turkey sights to improve your sighting. Then try different rifled slugs to find what works with your combination. Every gun is different but at $2-3 a box experimenting isn't very expensive. I agree with others that 3" slugs are a waste to even try. With a little shooting you should be able to find a slug that wil deliver 2" gropus at 50 yds.