Does a Sawed-Off Barrel Really Spread Out More?

[JohnnyAppleseed]

I went to the Box O Truth website but couldn't find any test done like this.

Take a single shot shotgun, any gauge. Shoot it and say it gives you a 9" spread at 15 feet (hypothetical). Let's assume it has a 26" barrel.

Now cut the barrel off 10 inches (yes I know you'd have an illegal 16 inch barrel at this point, but go along with me anyway). Will your ammunition really spread out more or is this an old wives tale (or hunters tale)?

I've always been told that the shorter the barrel, the bigger the spread, but this could be one of those Mythbusters things that has no basis in truth.

Anybody have real-life experience with this and not just stories you heard?

[7.62 FMJ]

I would think it would actually spread out less as measured from the muzzle due to a decrease in velocity. There would probably however be a larger pattern as measured from the trigger.

[Max-the-Silent]

I went to the Box O Truth website but couldn't find any test done like this.

Take a single shot shotgun, any gauge. Shoot it and say it gives you a 9" spread at 15 feet (hypothetical). Let's assume it has a 26" barrel.

Now cut the barrel off 10 inches (yes I know you'd have an illegal 16 inch barrel at this point, but go along with me anyway). Will your ammunition really spread out more or is this an old wives tale (or hunters tale)?

I've always been told that the shorter the barrel, the bigger the spread, but this could be one of those Mythbusters things that has no basis in truth.

Anybody have real-life experience with this and not just stories you heard?

In my experience, there is little to no increase in spread from a 13.5" barrel on an Ithaca stakeout over a 20" Ithaca DSPS using oo buck at 15 yds.

There is however a hell of an increase in muzzle blast.

That "take out the wall" stuff is a Hollywood invention.

[dexter9659]

This is a simple matter of physics. The little shot bounces around inside the barrel until it reaches the end of the barrel at which point it continues on its current vector, until other forces ie gravity kick in. The more distance the shot travels down the barrel, the more times it will bounce and straighten out (too a point). Shorter barrels give less distance for shot to straighten out and should therefore yield a spread which increases at a faster rate. Imagine a shotgun with a 2" barrel. When fired where would you expect, the shot to travel? Everywhere! Toss on a longer barrel, and the shot will begin to show a dispersal pattern. Of course if you add a choke.... things change. This all of course is what should happen. I am sure someone here has done measurements and tests on this very question.

[TRAP55]

Shot doesn't bounce around in the barrel unless you're shooting a muzzle loader. It's contained in the plastic shot cup, and stays there until the cup starts to open up about a foot from the muzzle.
Barrel length has nothing to do with the shot spread, the choke does. A 30" bbl with a full choke, will pattern near the same as a 20"bbl with a full choke. The fixed choke in a bbl is in the last 4-6 inches of the bbl. If you shorten the bbl and cut the choke off, you'll have a Cylinder bore, and thus a have larger pattern at a shorter range.

[Knight]

I remember there was some gun rag (I think it was Small Arms Review) that obtained an SBS manufacturing license or some junk, took a single-shot 12-gauge, and cut the barrel into various lengths, measuring velocity and spread each time they did it. A really cool article, too bad I no longer have the issue and can't remember much else about it.

[ysr_racer]

[cal_gunner]

I remember there was some gun rag (I think it was Small Arms Review) that obtained an SBS manufacturing license or some junk, took a single-shot 12-gauge, and cut the barrel into various lengths, measuring velocity and spread each time they did it. A really cool article, too bad I no longer have the issue and can't remember much else about it.

Contrary to popular belief, shortening the barrel of a shotgun has little effect on the spread of the shot, unless the barrel is made very short. Small Arms Review Magazine conducted a test in February 2008 in which they cut down the barrel of a shotgun a little at a time, firing it and recording the velocity (with slugs) and spread (with buckshot) after each shortening. With a 30" barrel, the spread was 10" at 15 yards. 24" barrel, about 11". 18" barrel, 8" of spread. 12" barrel, 12.5" spread. And with a 6-7/8" barrel, 17" of spread.

The main effect of shortening is a reduction in velocity, and consequently, the power and range of the weapon. Though again, this is not especially pronounced until the barrel length is decreased below 12". In the aforementioned tests, the velocity of a 1 ounce slug was 1,117 feet per second from a 6-7/8" barrel, compared to about 1,560 fps for a full-sized shotgun.

[Lee F. Smith]

It's kind of a hold over from before the choke systems. Long barrels had full chokes and the shorter upland game guns had more open chokes. So if you took the long goose gun and wacked off the barrel it opened up to cylinder resulting in a wider pattern. So it is 20% fact and 80% bull.

[Knight]

Contrary to popular belief, shortening the barrel of a shotgun has little effect on the spread of the shot, unless the barrel is made very short. Small Arms Review Magazine conducted a test in February 2008 in which they cut down the barrel of a shotgun a little at a time, firing it and recording the velocity (with slugs) and spread (with buckshot) after each shortening. With a 30" barrel, the spread was 10" at 15 yards. 24" barrel, about 11". 18" barrel, 8" of spread. 12" barrel, 12.5" spread. And with a 6-7/8" barrel, 17" of spread.

The main effect of shortening is a reduction in velocity, and consequently, the power and range of the weapon. Though again, this is not especially pronounced until the barrel length is decreased below 12". In the aforementioned tests, the velocity of a 1 ounce slug was 1,117 feet per second from a 6-7/8" barrel, compared to about 1,560 fps for a full-sized shotgun.

That sounds like the one. Thanks for posting a summary.