Like others have said, try a few different rifeld slug factory loads. One should group well. At 75 yards you'll be good to go. And as others have also said, if you can go the route of buying a rifled barrel for your Rem. 870, do so. Effective range will be increased substantially. I see no reason to buy a seperate "slug gun" unless you just want another firearm. One of my long time hunting buddies deer hunts with a Rem 870, rifled barrel set-up with a low power variable Leupold Vari-X III compact. He has killed many a deer cleanly out to 125-150 yards.