What sort of accuracy should I expect at 100 yards from slugs fired from a smoothbore shotgun?

Question

A lot of deer hunters put a rifled barrels on their shotgun and shoot sabot slugs. I know that without rifling a sabot slug has no stability.

But there are two common types of slugs designed for smooth bores:

1. Brenneke (a.k.a. European) slugs are cast with spiral grooves that supposedly impart some spin from aerodynamic forces once the slug is out of the barrel.
2. Foster (a.k.a. American) slugs are cast with hollow and/or finned bases to maintain stability in flight (due to the center of mass being in the front to prevent upset).

I've shot both kinds out of an unchoked barrel and been less than impressed with their precision: From a bench rest I don't think I've seen extreme spread less than a foot at 100 yards. But I have no idea whether this is actually bad or if that is the limit of precision on a smoothbore.

So what is the best accuracy I should expect from shotgun slugs in a smooth barrel, shooting from a bench?

Answer 1

No better than 3 MOA, probably more like 6 MOA, and they aren't very effective past 75 yards because they quickly loose velocity and start tumbling end over end.

A smooth bore firearm is simply never going to demonstrate the same level of accuracy as a rifle and will never excel at distances much past 100 yards with 75 yards and closer being the weapon’s ideal zone.

Extolling the virtues of the smooth bore slug gun

Slugs are better now. To 75 yards they have become extremely accurate. My current favorite is Brenneke's K.O. , which has an attached plastic wad that works like the tail of a badminton bird to keep the the slug flying straight. Stores around here stock huge piles of K.O.s prior to deer season and sell them for very little. At 75 yards they will shoot 1 ½" to 2" groups all day, which was unheard of when I started deer hunting. At 100 yards they usually print 3"-4" groups but the K.O., like any smoothbore slug, often loses stability somewhere between 75 and 100 yards and one may tumble far off target.

Smoothbore Shotgun Slugs: Then and Now

A smoothbore "slug gun" with rifle sights will usually shoot groups in the 3" (6 MOA) range at 50 yards/meters, making them satisfactory deer hunting weapons at short range. An occasional example will do better, and some do worse. Their effective deer hunting range is limted by their accuracy, but the slug itself is dangerous to other hunters at far greater distances, an important point to keep in mind.

Shotgun Slugs

Shotguns aren't usually used for their accuracy, but at the same time whitetail deer (probably the most common application for slugs) have a kill zone 10 inches in diameter, so you should be fine with a shotgun out to 100 yards with 6 MOA (which of course will depend on your gun and the conditions).