What does a longer barrel add to a rifle's ability that a shorter one gives up ?

[DuncNZ]

The accuracy of a firearm is depended on action , stocking , barrel, sights and load
With iron sights the greater the distance between the rear and fore sight the better the accuracy you get from the sights , This is why handguns with very short sight spacing may not be as accurate when hand held as when fired from a mechanical rest

 

[rusticbob]

The accuracy of a firearm is depended on action , stocking , barrel, sights and load
With iron sights the greater the distance between the rear and fore sight the better the accuracy you get from the sights , This is why handguns with very short sight spacing may not be as accurate when hand held as when fired from a mechanical rest

Wrong about the longer distance, Our eyes cannot vocus on three different distances at one time. Rear sight, front sight and target, one of them needs to be a slight blur, it’s the physics of the eye.
If greater distance between the sights was better for sighting, why do many ,if not all of these long barrel guns seem to have the rear sight half way down the barrel, they are at least a foot from the eye. A rear mounted peep sight works because your eye looks thru it, not at it. With eyesight as with everything there comes a point of diminishing returns. Your ideas might work with handguns where the sights are rarely more than 12” apart, but with a long barreled rifle the sights can be as much a 36” apart.

 

[SOLANCO]

Wrong about the longer distance, Our eyes cannot vocus on three different distances at one time. Rear sight, front sight and target, one of them needs to be a slight blur, it’s the physics of the eye.
If greater distance between the sights was better for sighting, why do many ,if not all of these long barrel guns seem to have the rear sight half way down the barrel, they are at least a foot from the eye. A rear mounted peep sight works because your eye looks thru it, not at it. With eyesight as with everything there comes a point of diminishing returns. Your ideas might work with handguns where the sights are rarely more than 12” apart, but with a long barreled rifle the sights can be as much a 36” apart.

You do not focus on the rear sight. As with the rear mounted peep you center the front bead or blade in the notch or horns of the rear sight.

 

[DuncNZ]

. Young eyes with perfect vision can focus between the back & front sights and target so rapidly that everything appears in focus .
There are a number of antique rifles in existence where the rear sight has been moved up the barrel in steps when the owner's eyesight has changed with age .
One advantage of a longer barrel is higher velocities for the projectile as the barrel length increases , Check out the Lyman Black Powder manual .

 

[Gordoncourtney]

From reading many of these posts it appears that many long barrel aficionados just want to be seen with there long barrels buy other people. And that is perfectly fine and to each his own. But from my perspective long barrels are a pain in the ass. I am primarily a hunter, and target shooter. My short barrel “carbines” hit just fine under the back seat of my Avalanche. Let’s face it, unless you walk to your hunting grounds, or shoot mostly in your have to someday transport that long gun sometime in a vehicle. My short guns are much more lighter and more maneuverable in the thick woods where I mostly hunt ,here in Vermont.
I don’t play dress up ,and I could not care less what other people hunt with or carry. To each his own, but I think my short rifles and shotguns shoot just as accurately as I will ever be able to hold.
And I have two grandsons who will find it much easier to learn on a well fitted, proper sized gun.View attachment 144795

I guess in those by gone days they found that long barrels were best , with poor quality powder made for cannon simple as that

I am down to 30” on my .36 Bp percussion double rifle 1885

Then 24 “ on my double 460-400 nitro Bp shoots well in a modern 12bore shotgun 28” barrels. I really love long barrels. I don’t like carbines as I ant got a horse , I guess it’s whatever make you happy , or just follow Favy Crocket and follow my leader. It’s a lovely subject to discuss

 

[The Appalachian]

All of the above is good info if I read it all right. One thing not mentioned is the universal truth that you can achieve a complete burn with heavier charge weights better in a long barrel as opposed to a shorter one.

A complete burn is one element of consistency, and consistency leads to better accuracy.

With modern rifles this is addressed with the burn rate of the powder. A shorter barrel will be at its best with a faster choice of smokeless powder, and the longer barrel will be happy with a slower burn rate powder. If you know anything about reloading metallic cartridges you know there are almost 200 choices on the burn rate chart to cover all the different chamberings out in the wild.

We don't have anywhere near that many choices with black powder even included all those substitute choices. And all our choices are too similar in burn rate anyway.

So with BP we adjust our charge weight to help compensate for barrel length. All you need to do is fire a shorter barrel with a heavier charge over snow or an old bedsheet to see how much unburned powder is being pushed out on the ground.

(Note: Smokeless powder doesn't generally fall on the ground, it produces a large fireball when the bullet exits.)

Unburned black powder or subs does nothing for efficiency or consistency or accuracy. All it does is take up space in the chamber, and waste your money with the cost of components.

So, knowing that explanation, the short answer is, you'll achieve the best load in a shorter BP barrel with a charge weight smaller than you would use in a longer barrel. The longer barrel load has more barrel time to complete the burn.

Infact that's part of how I tune/tweak a BP load. I adjust charge weight in 5 grain increments until I get unburned powder. Then I know my charge weight range for that particular barrel is the starting charge up to the charge weight just before I get unburned powder.

 

[SlidePicker]

Another thing: If you're tall and a stand-up fellow, a long barrel puts the muzzle at a handy height for loading operations without having to bend over. Less likely you'll inadvertently get vital parts in front of the muzzle as you're doing it, too. I suspect the ease of straight stand-up loading is an important reason why muskets were long, along with having extra reach with a bayonet.