When I shot a rifled 870 I used to use the Remington Copper Solids with very good results. This past year I sighted in my new 870, which does not have a rifled barrel, with the cheap old winchester rifled slugs and got very good accuracy out to 75 yards. Out to 100 yards the drop really came into play but still pretty decent groups. My suggestion would be to start cheap and then work your way up to the more expensive stuff.