whats the accuracy of rifled slugs outa a 20 inch cylinder bore with rifle sights? whats the range for hitting a deer with this combo?thank you

I made a slug gun by cutting the barrel of an old Stevens bolt action 12 Ga to 19" and adding williams sights. I added a stumpwood walnut foreend tip and pistol grip cap to the walnut stock and then added a decelerator pad and refinished the stock and checkered it. It's a pretty nice rig for a slug gun and I sight it at 25 yards where standard Winchester rifled slugs will make a 1" group. I'm very happy with this and consider the range to be 100 yards.

75 yards max. with iron sights. Groups around 5" off the bench. I have also shot a mossberg smooth bore with scope on reciever at 50 yds. Federal forster type rifled slugs, 2 3/4" shells. Groups around 2 1/2" at 50 yds off the bench. The best accuracy with this type of round (rifled slug) is about 75 yards, accuracy drops off fast past 75 yards. Others may have had different results as my testing was with one brand of ammo. Just for the fun of it, i shot Federal forster type rifled slugs out of a mossberg 500 scoped cantilever rifled bore slug gun. At 100 yard the five shot group measured 8". This is 2 times the size of what i shoot with sabots. The rifled slug hit higher on the target then the sabot with the same scope adjustment settings.Ammo both Federal 2 3/4" shells, rifles slug and sabot.