Barrel length/effectiveness?

[The Baron]

T.N. Frank... I see that canoe gun is sold on the TOTW site. I hope you decided to get it and have fun. :v

 

[TN.Frank]

Nope, wasn't me. Jackie has another 20ga smoothbore up for sale anyway, with a 36" bbl that'd be more to my liking anyway. Just need to come up with the money. :hmm:

 

[CoyoteJoe]

Paul, I totally agree that there is little to be gained in trying to push bird shot too fast. I tend toward V.M.Starr's recommendation of equal volume loads which, according to the Lyman data, produce velocities between 1000 and 1100 fps.
However, you are still talking smokeless powder. It is generally agreed that modern shotshells reach their max velocity in 18-20 inches of barrel length. Beyond that point gas pressure has dropped to a level that no longer sustains acceleration of the shot load.
NOT SO WITH BLACK POWDER! The Lyman data does not list very long shotgun barrels but if you'll look at rifle data you will see that even with the lightest starting load a 43" barrel gains velocity over any shorter length. That means that pressure at the muzzle is still sufficient to overcome friction and accelerate the ball. That gas pressure can not but disrupt the shot column as it clears the muzzle.
I a giving MY theoretical explanation as to why, but it has been often demonstrated that short barrels, black powder and birdshot just do not make a good combination. That statement is not based on ballistic theory but on demonstrated results. Mike Brooks knows of what he speaks! :grin:

 

[paulvallandigham]

Joe: A 20 ga. muzzle loading smooth bore with a 2 dram load, and 7/8 oz shot gives a nice easy pattern typical of open cylinder bore guns. If you use a shot collar, you can improve the pattern to about modified. At 30 yds., its killing power is related solely to the size of shot pellet used. #8 shot works fine for dove; #5 works fine for larger birds like grouse,pheasant, and partridge.

As to barrel length, powder charges burn efficiently based on the size of powder used, the amount of resistence provided to increase chamber pressure quickly, and, of course a reasonable barrel length. 24 inches is more than adequate in the smaller gauges with reasonable loads.

Rifles offer a different problem, because the grooves do offer places for gase to escape, and keep the pressure low. They also reduce friction with the PRB, making it easier to move, reducing pressure in the chamber. When that chamber pressure reduces, you get inefficient burning, and more residue, other things being equal. Burning efficiency increases, and Pressures are raised in rifles when a filler is used between the powder charge and the PRB. Part of that is caused by not only the increase in mass, but also the fact that a filler will compress before it allows the gases to move the PRB. That time it takes to compress allows more burning, and pressure to rise in the chamber.

I would always prefer a longer barrel in the larger gauge shotguns, as the reason for using them is to be able to shoot increased shot loads, and that requires more powder, and longer barrels to burn it. A 30 inch barrel works, and a 36 inch barrel on a 12 ga. shotgun, particularly a double is about all you want. If you are shooting a punt gun, which can be 2 ga. or 1 ga. then, you need that 48 to72" barrel, but you also mount the thing on the bow of a boat, and the gun was designed to shoot large quantities of shot over a wide spread so that flocks of duck sitting on a pond, or river could be killed with one shot. Since market hunting is illegal, such guns are also illegal for hunting, and other than curios, there is no reason to have one, or try to shoot it. YOu could do as well with a mountain howitzer mounted on anything, and shooting shot! The 30 inch barrels on the howitzers, which were up to 4 lb. pieces, but typically 3 pounders, could handle as much shot as a punt gun, and be slightly more portable.

 

[pathfinderifh]

I like smooth bores be they "Rifles" or the more traditional shot gun or trade gun. Not being a scientist or a man of Letters, but one who loves to shoot, I've played with different types of firearms over the years.

I've found that longer barrels shoot better with either shot or round ball. I built a .58 cal Hawkens using a 32" smooth barrel. Didn't shoot fer manure. Had a spare 44" smooth barrel that I fitted to the stock for yuk's and giggles, it shot pretty darn good!{looked funny :redface: , couldn't hold well :shocked2: , just wanted to play :haha: }. Had the short barrel rifled and things were back to normal.

It was by no means a controlled experiment, but followed what my other smooth guns do.

The other post seem explain why.

 

[Rusty Old Gunns]

Nope, wasn't me. Jackie has another 20ga smoothbore up for sale anyway, with a 36" bbl that'd be more to my liking anyway. Just need to come up with the money. :hmm:

Frank,

I have a Jackie brown Canoe gun with a 24" bbl. It may not be historically correct, but it's a nail driver. I was getting clover leaf paterns at 35 yards. 60g 2f, .15 patch & .60rb. Will it hit a dear at 50? Sure thing. Will it bring it down? Probably. How is it with shot? I have absolutely no Idea, but what a Pi**er to shoot! Ya gotta love it.

I also have a TVM Fowler the previous owner cut down to 32" It loves round ball with wads not patches. This season I will develope some shot loads.

Having said all that, I have to admit that if the good lord told me I could only have one gun, it would be my TVM Fowler with the 42" Bbl.

I guess what I'm saying is they're all better than a first date with the prettiest girl in town, so go with what floats your boat, my friend. Just be sure it can do the job it needs to do.

 

[TN.Frank]

I think another big part of why barrels were so long "back in the day" was to cut down on noise. The further you put the muzzle from the shooter the quieter it'll seem to be. Since round balls were being driver super sonic they'd make quite a bit of noise from a short barrel, something that'd have been unplesent so make the barrel longer and you have a quieter shooting gun, unless you happen to be near the muzzle of your buddies gun when he fires it. LOL. There are probbly many reasons why barrels were kept long and just as many reasons why barrels were bobbed off short. I guess unless we can go back in time we'll really never have a proper answer. :hmm:

 

[paulvallandigham]

The main reason barrels were so long was to give a long sighting plain, to cut down on windage issues with POI vs POA. Those front sights were as thick or as thin as a gun maker made them, with no standardized measurements used. Brown Bess' use the bayonet lug, hardly an instrument of fine sighting! The long sight radius made it more likely that the shot would be on line, and then all the shooter had to do was to correct for elevation.

 

[Blivetmaker]

Sight radius was and is an important factor in choosing a barrel length. The length chosen ends up being an amalgam of all factors resulting in a usable firearm for the purpose. An eighteenth century musket had to function as a spear. Even if the soldiers proved they could maintain accuracy with a shorter weapon, they'd have to show how a shorter gun could function in the bayonet charge. Bad powder and long sight radius were probably the dominant factor in keeping the late eighteenth century civilian weapons quite long. Barrels got shorter as mass production and reliable supply became commonplace and better sights were developed. Military rifles stayed fairly long until the brass felt fairly sure that volume of fire would outweigh and prevent the necessity of reverting to pointy stick combat.
Finally you use what works for the situation you're in. :thumbsup:

 

[Hoyt]

I like the looks of 42" barrels, but for my hunting use I don't go any longer than 38". Main reason is the longer it is, the more you have to move it to get on your game.

 

[Deadeye]

I love my 20 ga. 42" Fucil de Chasse and it shoots great
but for whatever reason the 26" Renegade barrel that I bored out to 20 ga. shoots even better patterns and does it even with heavier charges.
They both shoot balls well. I believe sight radius was the main reason for long barrels, not better patterns.

 

:hmm: Everybodies mileage DOES vary, indeed.

 

[brubincam]

long barrels cause when the war was over they had ready to go fence posts....

 

By golly Rubincam, I believe ya hit on something there. :rotf:

 

[rich pierce]

Got two words. Manton doubles. Nuff said?