Barrel Length Ballistics

Adding or decreasing a few inches of barrel can enhance wingshooting

By Brad Fitzpatrick

I once asked a skilled skeet shooter why he strictly shot guns with 30-inch barrels. Certain that a long and detailed dissertation on barrel length would follow, I was a bit taken aback when the man looked at me, shrugged, and said, “I dunno, I just break more clays with 30-inch pipes than 28- or 32-inch barrels.”

There was no mention of balance, momentum, the Coriolis effect or anything. To that shooter, who has broken 100 clays straight, barrel length was a matter of feel. Surely, I thought, there had to be more to barrel length selection.

That conversation occurred about 20 years ago, and in the intervening decades I’ve done my best to filter out the truth and lies regarding barrel length. I wanted to know, I suppose, whether the truth was as simple as my skeet champion friend had suggested or whether some deeper, more divine truth about barrel length could be unearthed. And while I don’t claim to have all of the answers, I’ll happily relate what I’ve absorbed from shooters, gun manufacturers and hunters regarding the science and mythology of barrel length selection.

Muzzle Velocity Myths
A few years ago, I was tasked with determining how barrel length impacted muzzle velocities in shotguns. Testing the muzzle velocity of a shotgun with a chronograph is an imperfect science, since shot comes out as a string rather than a single projectile. It’s possible for the chronograph to measure the velocity of the wad and not the pellets, but I would at least have a baseline to determine the relationship between barrel length and muzzle velocity. It’s the sort of thing that precision rifle shooters and their ballistic computers obsess over. But does barrel length affect shotgun muzzle velocity, and should we care?

For the velocity examination I tested 12 and 20-gauge shotguns with interchangeable barrels. I used 1 1/8-ounce target loads for the 12-gauge evaluation, and for the 20-gauge evaluation I tested 1-ounce small-game loads. Barrel lengths for the 12-gauge test were 22, 26, and 28 inches, and for the 20-gauge portion I tested 24-, 26- and 28-inch barrels. The results are shown here:

As you can see from these velocity figures measured on a chronograph at 10 feet from the muzzle, velocity is impacted very little by barrel length. If you’re convinced that the velocity of the projectiles that you’re firing from your gun with a 30-inch barrel is significantly more than the velocity of that same load from a 22-inch barrel, I hate to inform you that the data disagrees. Is there a difference between the velocities generated in a 22-inch barrel versus a 28-inch barrel? Yes. Is it statistically significant or relevant to field performance in waterfowl guns? Sorry, no.

Weights and Balances
Now that we’ve divorced ourselves from the notion that barrel length has any real impact on terminal performance in waterfowl shotguns, should we throw our hands up and say that barrel length is immaterial? Not at all.

Shotgun barrel length impacts the gun’s sight radius, weight and balance, and those factors will impact how well you shoot. A lengthened sight radius will help you shoot more accurately, but while the difference between a 22- and 30-inch barrel is quite pronounced and significantly affects your ability to hit a moving target, the difference between 26- and 28-inch barrels, and 28- and 30-inch barrels, is far less noticeable. A longer sight radius may help you pick up a bird from time to time, but it won’t make a bad shooter good nor a good shooter great, and so it isn’t one of the primary factors that should affect barrel length selection.

Weight does matter, and so does overall length. Long, heavy guns are a burden, but how much gun length and weight affect your success as a waterfowler depends upon the conditions under which you hunt. If you’re one of the rare breed of freelance waterfowlers who traipse great distances to hunt in far-flung pockets of public land, well, maybe gun weight and barrel length make a major difference in your success or failure. However, if you’re like me (and most of the other waterfowl hunters reading this) you probably walk less than a quarter mile to tuck into a blind that offers plenty of room for a 28- or 30-inch barrel. For the vast majority of us, gun weight and overall shotgun length are not factors of the utmost concern.

This leads us to the final and perhaps most important factor relating to barrel length — gun balance. How your gun balances depends on barrel length and construction as well as the gun’s length of pull. Somewhere between the gun’s muzzle and butt you’ll find the balance point, and most shooters do well with a gun that balances between their hands at the breech. Particularly if you’re tall (like the skeet shooter discussed earlier), longer barrels often strike a better balance between a nose-heavy gun (too much weight in the barrels) and a whippy gun (too much weight at the rear of the gun).

For more evidence that barrel length is primarily a byproduct of balance, let’s look to the world of competitive sporting clays. A few years ago, 34- and even 36-inch barrels were becoming more popular among sporting clays shooters. The idea, I suppose, is that a longer barrel made you shoot better. Pretty soon, however, the tide turned and shooters were retreating back to 30- and 32-inch barreled guns and away from nose-heavy stack barrels. It’s rare now to see competitive shotguns with 34-inch pipes. Caesar Guerini is one maker offering them, but Guerini USA president Wes Lang, himself a competition shooter, says Guerini can lighten the barrels so that 34-inch guns balance properly on the front hinge pin.

A Fitting Choice
So, was the old skeet shooter right? It appears so. If you’re a small-statured shooter with a short length of pull, then you’ll probably find your firearm balances better with a 26-inch barrel. If you have long arms and a correspondingly long length of pull, then a 30-inch barrel will work best. The odds-on favorite for 12-gauge shooters is a 28-inch barrel. It balances well for a wide range of shooters and most production stocks, and that’s why it’s the most popular barrel length for semi-auto duck guns.

But, as my friend said many years ago, you have to find what works for you. When you do, you’ll break more clays — and kill more birds.

Brad Fitzpatrick is shopping for his next 28-inch barrel shotgun in Marathon, Ohio.