What;s optimal barrel length?

[capnwilliam]

It seems to me that many flinters, whether smooth or rifled, have VERY long barrels: 36, 42, 44 inches. Is there really any advantage to such a long tube? Does it help combustion and hence increase ignition that much, compared with say, a 30 inch barrel? Seems as though a shorter barrel would be much handier. ::

Capt. William

 

[Zonie]

IMO, a good part of the reason for the 42 inch (and longer) barrels is due to the desire to recreate authentic (or nearly so) guns.
42 inches or thereabouts was a fairly common length (or a good compromise at representing the originals of the late 1700s).

Now if the truth be known, 42 inches (3 1/2 feet) is rather short when compared with some of the old guns.
The Long Fowler of the latter part of the 1600s for instance was really looooong.

A quote from Arms and Armor in Colonial America 1526-1783 by Harold L Peterson, pp 42 quoting an old Massachusetts Bay document:
"..."6 long ffowlinge peeces wth muskett boare, 6 foote longe 1/2" and
"4 longe ffowling peeces wth bastard muskett boare 5-1/2 foote longe."

In Plymouth, Edward Winslow advised prospective colonists: "Bring every man a musket or fowling piece. Let your piece be long in the barrell: and fear not the weight of it, for most of our shooting is from stands."

These long guns, ranging in length up to seven and one-half feet, remained popular throughout the seventeenth and will into the eighteenth century. A number still survive..."


IMO, a good part of the reason for long barrels was the powder of the times was of a poor quality. The long barrels got the most out of this poor powder.

As time passed, and powder quality improved, the long barrels began loosing favor. By the time of the exploration of the Great Plains, many rifle barrels were in the 30-40 inch length and of course, for the Plainsman, the bore sizes began increasing.
I think the main reason some of these Plains rifles kept the barrels as long as they were was because they used rather heavy powder charges and the horse carried the weight of the gun.

 

[tg]

There are a lot of theories about the evolution of barrel length in the 17th century, contemporary balistic theory was one, the fact is that a 44 inch barrel on a gun is really not cumbersome at all in the brush once you get used to it.

 

[TANSTAAFL]

I like a long smoke pole leaner, and at three score plus I am coming to like them a lot. For I do more and more leaning, with less and less shooting. Heck, I can lean on that stocked 46 inch barrel and look cool as all get out, while I pontificate on just about everything that doesn't really matter a whit.

 

[Rat]

A longer barrel, unless you really go to extremes, will produce more velocity. There is such a thing as the projectile slowing down, in the barrel from friction, but that's pretty rare, and would require a VERY long barrel and realitively light powder charges. (I think)

I think it's only around 28 inches or so/or less where the "law of diminishing returns" sets in, with muzzle loader barrels of around .50" and up, but still the long barrel will be the more powerful one. A 40" barrel will produce more velocity than a 28" barrel, period. Just because velocity increases level out, and diminish after a certain barrel length, does not mean they are not still increasing as you add barrel length. Some people take the law of diminishing returns too literally.

The old timers knew that a long barrel "shot harder", but I think handling and the long sight radius were more imortant to people who grew up depending on one shot, or making that one shot count. A 40" barrel is not really that long, just sounds long to people raised on 22-25" barrels, and lots of repeat shots in the magazine or tube.

I also think that economy of powder and shot, when re-supply was difficult, favors long barrels. Packing a long barrel and using less powder, and getting a little more accuracy from the long sight radius was a good thing in the wilderness I bet. And what good is "handy" if it does nothing to ensure a one shot kill?

Really pinning down "optimum" barrel length would be pretty hard. It would/could be very different depending on calibre, and what power level you plan to load up to.

With heavy, large caliber barrels, weight considerations might make a shorter barrel more optimum. To get the most power out of heavy loads though, I would think a longer barrel would be more optimum. This could be kind of a "conflict of optimums"...!!!

:hmm:

What I understand from your post, is that you are asking what is most optimum ballistically. In that case I'd say something in the 40"-42" range would be most ballistically efficient, law of diminishing returns not withstanding.

It's probably no accident that rifle barrels eventually "evolved" to the 40-42" length, on average, and didn't begin "shrinking" until the cartridge gun became the norm.

40" barrels are not un-handy...they sound much longer than they feel when you actually hold a rifle with a 40" barrel. Really a 36" barrel is not long at all...I'd call that a mid-length barrel. My Bess and Jaeger both have barrels in the 31" range...I'd call those short, but still long enough to be quite ballistically efficient, and produce all the velocity I want. But using the Jaeger as an example, if I shot it side by side with an identicle rifle with a 40" barrel, I'd have to use a heavier powder charge/more powder to produce the same velocity.

Having said all that, :yakyak: probably the only true way to come to the optimum barrel length would be to find the barrel that produced the velocity you wanted, with the kind of powder charges you wanted to shoot, within ten grains or so....and still be within a few inches of what felt "handy", or had good handling, in your opinion.

Did that make ANY sense?

:youcrazy:

Rat

 

[rich pierce]

Rat makes good sense. Also, optimal for some of us is a barrel length that is historically accurate for the type of gun we like to carry.

 

[robinghewitt]

Historically, experiments with cannon showed that there was no real advantage to going longer than 25 calibres. Whitworth made a pair of 60.5" barreled, 4 band rifles, one of which was sawn off on inch at a time for testing to disprove the myth that longer was better. The British Army experimented with sawn off Bess's in 1769 and found you could drop to a 20" barrel without loss of range.

 

[Bearbait2]

Squire Robin,
A "...20" barrel", now that is interesting! Did your documentation provide muzzle velocities (using the method of the day) as well? Just curious.
Best Wishes

 

[aragorn]

I thought one reason for the long Bess barrel (and other muskets too) was that muskets were still looked upon as pikes, i.e. as bayonet poles, and the longer the pole the more effective it was rammed into the ground against horses or in a charge against a line.

The same mentality persisted into the 20th century, with old tactics dying hard - apparently that was one of the offical objections to the British shortened Lee-Enfield rifle when it was introduced (the Short Magazine Lee-Enfield, SMLE), and was supposedly one reason why the long sword bayonet continued in use on these rifles in WW1 (the 'pig-sticker' of WW2 was generally thought more effective). The bayonet continues to be a major weapon in the British army today, with e.g. much bayonet use in the Falklands War, though ironically the British are now equipped with one of the shortest rifles around, the bullpup SA80 (yet used in at least one reported bayonet charge in Iraq).

On a different note altogether, I'm tall and find a long rifle (42" plus) easier and safer to load with the barrel facing well away from me while it's resting comfortably in the crook of my arm, whereas 36" or smaller is too short for me and I have to find something to lean it up against.

 

[jim gray]

It seems to me that many flinters, whether smooth or rifled, have VERY long barrels: 36, 42, 44 inches. Is there really any advantage to such a long tube?

Ballistics and powder combustion aside, there is one other advantage to longer barrels in that they give you a longer sight radius, and this equates to better accuracy. The greater the distance between the sights, the more precisely they line up when you aim.

 

[robinghewitt]

Squire Robin,
A "...20" barrel", now that is interesting! Did your documentation provide muzzle velocities (using the method of the day) as well? Just curious.
Best Wishes

No velocities given, but similar experiments done around 1810 worked with saturated elm wood boards, 1/2" thick and spaced 3/4" apart in a frame, shot from 60 feet with 14.5 gauge balls over 6 drams of powder. Penetration varied from 8.9 to 10.8 boards.

Extensive web searching has not yet come up with a saturated elm board to fps converter ::

 

[Stumpkiller]

One of the reasons I've heard bandied about is that the older firelocks used longer barrels because the available powder was often dubious and the longer barrel assured complete ignition.

Seems to me if it ignites at all you're home free, but that was something I've heard/read. I suspect some of the smoothbores lengthened the barrel before choke were invented/understood. Some of the Hudson River and Club Butt Fowlers are astoundingly long (like Robin's 60" bbl goose pike :shocking.

 

[sherpadoug]

Historically, experiments with cannon showed that there was no real advantage to going longer than 25 calibres.

What about WWII anti-tank rifles? Some of them were 50 cal. with very long barrels, burning modern fast powder. 25 calibers would only be a foot long! I think there are a lot more variables here.

 

[Rat]

Wow...Mr.Squire I'm having trouble accepting that a 20" barrel produces the same velocity as a 42 incher.

:cry:

Usually when you cut a barrel down one inch at a time, you'll see small velocity losses at first, and as the barrel gets shorter they become bigger.

If you cut a musket barrel down from 42" to 20", and shot it at 100 yards, you might not see "loss of range". ?? But at long range velocity will make a difference.

On the board test, I've done extensive penetration testing with cartridge revolvers, through wet fir boards, and found that with softer bullets that deformed, penetration often did not decrease with a decrease in velocity, because as velocity decreased, the bullets deformed less, and therefor penetrated better. Perhaps that was what was really going on with the experiment using wet elm boards you mention, as most likely very soft lead balls were used. ??

A 60" barrel, with a light service load, might indeed show no velocity loss for quite a few inches. But eventually, perhaps around 40" you'd start seeing a drop, that would increase more and more as the barrel got shorter. With REALLY HEAVY loads, I bet the 60" barrel would produce quite a bit more velocity than a shorter barrel.

Just a thought.

Rat

 

[BLAHMAN]

Squire Robin,
A "...20" barrel", now that is interesting! Did your documentation provide muzzle velocities (using the method of the day) as well? Just curious.
Best Wishes

I made a 59 caliber gun with a 24 inch barrel....shoots pretty good...I don't know about 'velocity' per se, however, I do know that when you put more than 80 grains of 2F in the thing, the recoil become much stiffer. It prints a very decent group at 25 yards, but at 50 yards the group opens up. At 75 yards the group is questionable. At 100 yards, well, let's just say the ball comes out the barrel.

I actually enjoy shooting it, and I use it as a squirrel gun.

Now, you're probably asking yourself: "Squirrel gun???? A 59 caliber squirrel gun????"

Yup, that's right, and here's how it works: There are actually two ways to get a squirrel with this gun. The first is to spot the squirrel, let it run into a tree, then shoot the tree, tree falls down, squirrel deads from concussion.

The other way is to put 10 grains of powder in the barrel, then place small acorn in the barrel and lean the gun against a tree. Eventually, the squirrel will smell the acorn in the barrel and crawl down the barrel....at that point you simply aim the gun at the tree and "POOF" the squirrel will get thumped up against the tree. :haha:

 

[Rat]

Blahman, I think YOU are getting kind of squirrely...!!

:nono: :blah:

 

[BLAHMAN]

Blahman, I think YOU are getting kind of squirrely...!!

:nono: :blah:

Thanks for the compliment...where else but here can one feel so loved? :thumbsup:

 

[robinghewitt]

What about WWII anti-tank rifles? Some of them were 50 cal. with very long barrels, burning modern fast powder. 25 calibers would only be a foot long! I think there are a lot more variables here.

Modern powder is different, burn rate changes with pressure, but don't take my word for it...

Cool Cannon Link

 

[Stumpkiller]

They determined that the maximum ranges given by Collado, fol. 27, and all of the ranges given by Prado y Tovar which were subjected to analysis would have been attainable only with muzzle velocities in the neighborhood of 6,000 feet per second, nearly five times the speed of sound and almost three times the muzzle velocities of modern small arms.

:shocking: :shocking: :shocking: That's some cannon! :shocking: :shocking: :shocking:

Further historical documentation that figures don't lie . . . but liars figure. ::

 

[RussB]

So far, I think I favor what Rat said here....."I also think that economy of powder and shot, when re-supply was difficult, favors long barrels. Packing a long barrel and using less powder, and getting a little more accuracy from the long sight radius was a good thing in the wilderness I bet. And what good is "handy" if it does nothing to ensure a one shot kill?"

I also know that Rat likes the 40" barrel of his muskets, while I find my own to be somewhat cumbersome. My own preference for "handiness" is 33 inches.

I also know that, at least on my chronograph, that the difference in identical charges,ie, Caliber, ball, patch, lube, everything, between a 28" T/C Hawken, and a 33" GPR is roughly 45fps in favor of the longer barrel.....but I don't contribute that to barrel length....necessarily.

I have fired my GPR with a particular load across the graph and come up with one reading, while others fire the same identical load in their GPR's, and come up with different readings...some are higher than mine (some by as much as 100fps), some are lower than mine....indicating their rifle with the 33" bbl was actually slower than my T/C with the 28" bbl using the same load.

To make a sound statement about this increase / decrease in velocity, I feel a person would need a very large test media of at least 100 rifles of each barrel length, but same caliber.

The one thing we can not ignore is the longer sight radius equates to better accuracy, and the Longer barrel is going to win this hands down.

The other is relative....is it important? To some it is, but to many it is not.
To me it is, simply because I would like to know. ::


Russ