The best of today's slugs and slug guns can deliver accuracy as good as many ordinary hunting rifles out to 100 yards, 150 yards, and even beyond. I have personally fired 5-inch groups at 200 yards with sabot-type 12-gauge slugs through interchangeable-barrel, full-rifled Remington and Mossberg autoloaders and pump shotguns. Using a dedicated "slug rifle" like Savage's Model 220F 20-gauge, those 200-yard groups shrink to under four inches.
If you haven't tried or witnessed new-generation slug ammunition or slug firearms in action, you may scoff, but the fact is, the world has changed. And, if you question a slug's "killing power," just note this: the retained energy of one of Remington's current 12-gauge Premier Copper Solid one-ounce sabot slugs at 100 yards is 1,364 ft/lbs. The retained energy of a traditional lever-action's 170-grain softnose .30-30 bullet at the same distance is actually nine ft/lbs less.
When I first began hunting whitetail deer with shotgun slugs nearly 40 years ago, it was because I had to. It was the only firearm my home state of Illinois would allow. The only choice was a Foster-type "rifled" slug in a smoothbore improved cylinder barrel with open-notch sights. Fifty yards was the maximum reliable shot. If you tried to push it much past that, you'd be just as well off throwing rocks. Today, there is a wide variety of new slug designs and whole bunches of new guns and new barrel designs in which to shoot them. In many areas today you are as likely to see a whitetail hunter with a fully-rifled, factory-made, synthetic-stock bolt-action slug gun and a 3-9x scope, as you are to see one armed with a traditional lever-action .30-30 deer rifle.
At the same time, there are thousands -- even tens of thousands -- of long-term deer hunters still using their favorite do-everything shotguns with smoothbore barrels -- either with or without "rifle" sights -- to harvest deer with the same Foster-type slugs as a generation ago. But today's slug-gun hunter has nearly as many different options available in gun and ammo types for different ranges and hunting environments as does a high-power rifle hunter. This is a new thing, and also a good thing, since there are many states and intra-state hunting zones in this country where a slug gun is still the only deer-hunting firearm allowed by law.
Today, there are basically two types of slug ammunition on the market: either sabot or non-sabot (with numerous variations of each). Sabot-type slug ammo designs all utilize some type of relatively soft non-metallic sleeve material (usually polymer) that surrounds a smaller diameter bullet projectile. Bullet configurations and sabot designs vary widely by manufacturers and their types of loads, but all sabot ammo is based on the principle that the bullet "sheds" the enclosing sabot in flight (through wind resistance or the centrifugal force of spin imparted by rifling) or on impact. Non-sabot ammo utilizes a bore-diameter projectile. In terms of how these slug types perform, it's the bore that counts. The type of shotgun action -- auto, pump, bolt or break-open -- is not really significant.
Similar to a musket, a smooth-bore slug barrel does not spin its projectile. Its barrel has no rifling, so range is limited to not much more than the best modern archery tools. A smoothbore barrel with a screw-in rifled choke is somewhat better, because it will impart at least some stabilizing spin to a departing solid or sabot-design slug and will put you on an equal range footing with a handgun hunter using a .44 Magnum-category revolver. A full-length-rifled slug barrel is best and reaches out into centerfire rifle territory.
You can safely shoot all types of slugs in all types of barrels, but if you use premium-grade sabot ammo in a smoothbore, you're wasting your money and you will likely get less accuracy than with a conventional Foster-type soft lead slug. When shot from a smoothbore barrel, a sabot won't spin, won't properly separate from the bullet and will actually de-stabilize the trajectory more than a solid-type load.
On the other hand, if you shoot an old-fashioned Foster lead slug through a rifled barrel, you'll get much more accuracy with it than through a smoothbore. Rifling does work, after all.
So does this mean you should immediately junk the smoothbore deer-slug barrel you've been using for years and run right out and buy a new full-rifle barrel or entirely new slug gun? Not necessarily. It depends on what you really need for your particular hunting circumstances. The most important thing about all the different new types of slug loads and slug barrel designs on the market today is that they offer slug gun hunters a full range of choices -- just like high-power rifle hunters have had forever.
SLUG GUN TECHNIQUE
As for slug gun tactics, these days that, too, depends on the type of slug tool you're using. If you're using a smoothbore, you need the skills of a bowhunter. With a rifled-choke slug gun you need to think like a revolver hunter. With a bolt-action full-rifled sabot slug gun, you can think like a 200-yard rifle-cartridge hunter.
I've long believed that the limitations smoothbore slug guns imposed upon traditional Midwestern deer hunters caused them to develop considerably more effective skills and hunting techniques than high-power rifle hunters who could stand back and whack animals they saw out to a quarter mile. Good slug gun hunters had to learn to hunt tight, careful, close-in. Those skills and techniques were already part of their feature set when the recent revolution in sabot-slug ammunition and rifled-bore slug gun technology transformed their tools into reliable 150- to 200-yard performers.
That one fact -- that Midwestern slug hunters today possess a unique combination of close-range technique and extended-range tools -- explains a great deal about why slug hunt areas like Pike County, Illinois, or the Loess Hills of Iowa, have in the past few years become some of the most productive trophy whitetail locations on the continent. And at the same time, fully 65 percent of all slug ammunition sold in the Midwest today continues to be traditional Foster slugs. So traditional slug-hunter skills are not being lost, and deer hunters who adopt Midwestern slug-hunter techniques for wherever they hunt with whatever their tools, will be ahead of the game.
Moreover, traditional smoothbore slug guns actually have an undeservedly bad reputation. The thing most often heard is that smoothbore slug guns aren't very accurate and wound and cripple too many deer. In fact, no state or federal wildlife agency has ever developed any statistics to show slug guns are either more or less effective than any other type of firearm when it comes to harvesting deer-within their effective range. Which is merely another way of saying that there is no evidence to support any notion that slug gun hunters wound, maim, or cripple any more deer than do rifle hunters, bow hunters, black-powder hunters or handgun hunters. What does happen, however, is that a lot of hunters using shotgun deer slugs do not use them correctly and, therefore, do not get the kind of results from them that they'd like.
Many skilled shotgun shooters have a tendency to shoot slugs the same way they shoot shotshells--they just point and slap the trigger. That works fine if you're throwing out a cloud of pellets that can cover a 30-inch target circle by the time they're 30 yards from the muzzle. But it doesn't work for a slug, which is a single projectile that has to be fired with the same careful aim you'd use with a rifle.
The problem is worsened by the fact that it is perfectly safe to shoot slugs through the same shotgun barrel you use for hunting quail or ducks, and a lot of deer slug hunters do just that, rather than spend the money to get a real slug barrel with rifle sights to put on their shotguns. Ordinary shotgun barrels don't have sights, just a bead to help center the shot pattern on a flying bird, which isn't much help trying to carefully aim at the chest of a deer that's standing 50 yards away.
The other side of the coin regarding slug guns' bad reputation is that when many shotgun shooters get a slug barrel with rifle-type front and rear sights and put it on their shotgun, and charge it up with new high-tech sabot loads, and maybe even mount a scope on it, they start acting like they have turned that shotgun into a real rifle. They start trying to make the same shots they would try if they had a .308 in their hands. But they don't.
A slug gun is still a shotgun, firing ammo with a muzzle velocity of less than 2000 feet per second. It still has a limited range compared to any high-power rifle, and must be used within its limitations.
So all slug guns, both traditional and "modern," are often misused in two entirely different ways: either by hunters who try to shoot them like they were firing shotshells, or by hunters who try to shoot them like they were firing a high-power centerfire rifle.
A slug gun is neither a shotgun nor a rifle; it is what it is -- a slug gun. If you use it the way it's designed to be used, it makes a fine deer-hunting tool. Whatever slug gun system you choose -- whether you shoot traditional Foster-type slugs through the same smoothbore barrel you normally use for bird hunting, or get a scope-sighted full-rifled barrel and use new sabot slugs -- the most important thing you should do is take the gun and the slugs to a shooting range and sit down at a benchrest and actually shoot the slugs at a target to see where they're going at the effective ranges.
There is nothing wrong with using a 30-inch full-choke waterfowl barrel to shoot slugs at deer -- as long as you know where it shoots and how to aim it to hit where you want. One member of my local deer-hunting group has filled his tag every year since the 1970s using Foster slugs in a 30-inch smoothbore full-choke duck barrel on his Remington Model 870 pump. He puts a receiver-mounted low-power scope on it for deer season, sights it in carefully, and never takes a shot past 50-60 yards. And he always scores.