Shotgun Confusion Cleared

Kids ask the wisest questions: “Why are shotgun names and numbers so weird,” a nephew wondered.

“Because ‘old fashioned’ people invented them,” I said. But he needed more explanation than that. We all do.

Ron Spomer

First, shotguns are measured by gauge instead of bore diameter. Gauge is determined by melting a pound of lead into individual balls that fit the bore diameter of any gun. The fewer balls to the pound, the lower the gauge number, but the bigger the bore size.

Like the nephew said, weird. So if one pound of lead yields 12 balls that fit the bore diameter, it’s a 12 gauge. Twenty balls means it’s a 20 gauge and so on except (there’s always an exception, eh?) the .410, which really is a bore diameter of .41-inch. If you were to melt a pound of lead into .41-inch balls, you’d get 68 of them — a 68 gauge.

From left: 28 ga., 20 ga., 12 ga., and 12 ga. Shotshells come in different gauge sizes to fit specific guns, and they carry different quantities of shot pellets that are different sizes and materials.

Back when guns were made one-by-one, barrels often came out with odd bore sizes, so folks hunted with 17 gauges, 24 gauges, even 8-, 5- and 4- gauges. Those last two would knock you on your butt, believe me.

Today things have settled into just a few common shotgun sizes. Starting with the largest, there’s the 10-, 12-, 16-, 20-, 28-, plus the tiny .410 bore.

Another way to understand this is to match the gauge to actual bore diameter, like this:

10 ga. = .775-inch

12 ga. = .729-inch

16 ga. = .663-inch

20 ga. = .615-inch

28 ga. = .550-inch

.410   = .410-inch

So, the lower the gauge number, the bigger the gun. But that’s hardly the end of the numbers.

There’s barrel length, too. For hunting these generally run from 24-inches long to 30 inches. Most hunters favor a 26- to 28-inch barrel. Longer barrel shotguns do not shoot farther or hit harder, but they maintain momentum, which helps shooters maintain a critical “follow through,” which prevents stopping the swing and shooting behind a moving target. Some turkey hunters like shorter barrels because they’re easier to carry through thick woods. Most turkeys are shot in the head as standing targets, so “swing” has no bearing on success.

Which gauge is best? Depends on your needs. The larger bore sizes can fire more shot (pellets) and handle larger pellet sizes more efficiently, so the 12- and 10 gauges are better for throwing big pellets at big birds such as geese. Smaller bore sizes make for lighter, faster handling guns, so they’re better when you need to shoot quickly at grouse or quail. They perform best with smaller pellet sizes.

It’s important to know that large gauges do not necessarily shoot faster or farther than small gauges. The total weight of the payload (shot charge) is driven to relatively standard velocities in all gauges, and pellet size determines how much energy each pellet will retain downrange. But, because large gauges start out with more pellets in a charge, they can hit harder by delivering more pellets to the target. But that doesn’t always happen. Why not? Blown patterns.

A Winchester (black) BlindSide 12 ga. shell showing internal parts. A typical shotshell consists of a primer (not shown) in the base to ignite the powder.

When hundreds of pellets in a charge of shot fly downrange, they spread out. The farther from the muzzle, the wider the spread of the pattern. It’s possible for a 20 gauge to put more of a given shot size on target than a 12 gauge, depending on factors such as choke, pellet hardness, wad configuration, and more.

As a general rule, the most versatile shotgun these days is a 12 gauge chambered to handle 3-inch shells. That means you can also shoot 2-3/4-inch shells through it. By selecting different charge weights from 1-ounce to 2 ounces, and shot sizes from 9-shot (small) to BB (large,), you’re set for just about any bird that flies or bunny that bounces.

Visit Sportsman’s Guide for a fine selection of Shotgun Ammunition.

Ron Spomer has been photographing and writing about the outdoors for nearly four decades. He’s written seven books, hunted on six continents and been published in more than 120 magazines. He’s currently rifles’ editor at “Sporting Classics,” Travel columnist at “Sports Afield,” Field Editor at “American Hunter” and “Guns & Ammo” — Optics Columnist at “North American Hunter,” Contributing Editor at “Successful Hunter,” Senior Writer at “Gun Hunter,” and TV host of “Winchester World of Whitetail.” He will write on Shooting Tips weekly for You can read his blogs and catch some of his YouTube videos at


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3 Responses to “Shotgun Confusion Cleared”

  1. Mike Banks

    Hi Ron,
    I like supporting our local VFW and they occasionally hold Turkey Shoots (paper targets). What gauge and ammo would you recommend to a novice so I might have a chance with the “regulars” at an open shoot? I would love to steal the show (so to speak) and beat those guys at least once.
    Thanks for all you do and have done for Shooting Sports and The right for all persons to have the opportunity to Hunt.
    Mike Banks

  2. William L. Ramsburg



      First let me say it has been over 50 years since I Attended a paper Turkey shoot . If the winner puts the most pellets in Head & neck area ! See what your shot gun likes ! May not be amag load often standard high brass in #6s or 4s will get the job done! But do pattern it sone will large spaces with no shot !! have fun be safe