barrel length and bore

[Hatcon]

I was wondering on a smoothbore flinter is a longer barrel and larger bore i.e. 46inch .78 any more accurate than say my 40inch .62.If so does one have any more range. I recently aquired a .62 smoothie and love it but I have only started working with it as to accuracy and at what range I can confirm reliable hits.

 

[robinghewitt]

Not everyone would agree with me on this ::

I'd say that round ball in a smoothy favours the larger calibers if you want accuracy and range.

0.75" is okay, but it gets better as you move up in to the realms of cannon. Once you have a cannon, only the first 25 diameters count, so a 1" bore need only be 25" long for best use of the powder. After that there is very little advantage to going longer.

 

[Rat]

I'm thinking that trajectories between the two would be so much alike that on that basis one would not out range the other, especially considering both would be used at ranges under 100 yards.

The bigger ball will have more energy at any range. Unless I was hunting grizzly bear I would not worry about the difference there. (in which case Robin's cannon or wall gun might be the best choice)

A longer barrel gives one a longer sight radius, which will improve accuracy, but a longer barrel, in it's self is not more accurate than a shorter barrel. All things being equal, a 10" barrel and a 50" barrel, both with a 50" sighting radius, would have equal accuracy.

Generally a longer barrel will increase velocity, which can increase range, especially with heavy charges, but the difference between a 46 and a 40" barrel would be very slight. You would see a more meaningful difference, in the long barrel's favor comparing a 30" barrel to one of 46". (or a 30" to a 36") Adding 6" of barrel length to a 40" barrel would see little gain.

I believe your 40" .62 calibre, when you have perfected your load, would/will plunk balls into a paper plate at 75 yards with the same consistancy as would a 46" .78 calibre musket or fowler. The .78 would hit a little harder when it got there though. As a .62 will kill Elk at 100 yards no problem, I certainly would not feel very under-gunned compared to the .78 with six more inches of barrel.

:no:

Rat

 

I'm in total agreement with the advantage being to the larger bore. As the Squire says, this tendency carries right up into the cannon sizes - or does it carry down from the cannons to the small bores we use?
: .75's are easier, in general, to get to shoot well at 100yds. than a 20 bore. The 20 bore, easier than say a .50 smothbore, and so it goes. There is probably a relationsip between bore size and range, ie: what the .80 does at 110yds, the .75 will do at 100yds & the .69 will do at 90yds, 20 bore at 80yds, etc. This is merely theory, and demands all else being equal- ball/patch size/fit, etc and equivalent powder charge.
: I believe there is a tendency to use 'too-little' a charge to get the best results from the big smoothbores - or big rifles for that matter. There's that "opinion" again.

 

[Rat]

It's true, as bore size goes up you see people still using powder charges appropriate to the smaller bores...lots of people afraid to put more than 80 grains of powder in a Brown Bess, when that's more of a normal charge for a .50".

However, when you do up the charge accordingly with the big bores, you start to get big recoil and I think that's the real reason there's kind of a "status quo" to load under 100 grains in the .69 and up smoothbores, and what are actually very light charges in a 20 guage.

In a .62" smoothbore I would personally charge it with at least 100 grains for a hunting load, and to be really truthful I would not be afraid to go up to 110 or so. With no rifling for the ball to jump heavy charges won't deteriorate accuracy, unless the recoil causes one to start flinching. I wouldn't load less than 100 grains in a .56 for sure, for hunting.

Rat

 

Rat, I think that you also have to clarify what sort of powder you use. I shoot 70gr of 3f in my 20 gauge with terrific accuracy and devastating effect.

I do agree that a larger ball travels straighter--I like a .62 much more than .54 in a smoothie--but I like the fact that I get twice as many balls out of a pound of lead in ye olde 20e gaugee.

:results:

 

[Russ T Frizzen]

One thing about long barrels-once you've got the ball moving at its maximum velocity inside the barrel, friction
losses begin to slow things down again. There used to be a web-site that showed this loss. They kept cutting the barrel back an inch at a time and for a while the velocity went up. Can't remember what length they started with and I can't find the site either.

 

[Rat]

I wuz speaking in terms of ffg...and don't have a 20 gauge smoothie, so I could be way off! I load 110 grains of Swiss ffg behind just about everything in my Brown Bess carbine. For grouse loads I drop that down to 100. But the ball definately shoots "just right" with the 110. (she has a bit of a kick to her though)

Where the ball ceases to accelerate in a barrel depends a lot on the powder charge. The heavier the charge, the more barrel you can use. A really light charge in a 40" barrel might peak out at 24", but add more powder and it might peak out at 30", and so on.

Rat

 

[robinghewitt]

They kept cutting the barrel back an inch at a time and for a while the velocity went up. Can't remember what length they started with

When Whitworth did the same experiment he started at 5 feet. He made two 4 band rifles, one for chopping up, the other is in the NRA museum at Bisley camp.

 

[Hatcon]

Interesting thoughts, very helpful. My reason for asking is that localy the thought on the matter is that smallbores tend to be more rifle like in their accuracy whereas largebores tend to be more akin to a modern shotgun with a slug. Me being one always looking for an excuse to aquire another smokepole thought I might convince myself to do so if there was a reasonable difference. Perhaps a wall gun? Now let me see .....

 

I did have a .44 cal smoothbore made from Shelby Seamless tubing - back in the 80's. I jug-choked it for shot and with ball it still shot well out to 50 yds. There's no telling where they went after that. I couldn't hit a thing at 70yds. Out to 30/40 yds. it was a very close grouper, as accurate as most of the 48" twist rifles (& their shooters) were,at that time. It would hold about 1 1/2" out to 40yds. I'm assuming the small ball took on a spin to hook or slice it out of the way much past the 50yds. mark.
: This is not meant as a disparaging remark at all. It is just that the less experienced shooters around here have the 'factory' guns & they themselves lack the accuracy of those more steeped in tradition & more interested in exacting accuracy of their loads.
: The larger the ball, it seems, the slower it is to take this accuracy destroying spin, therefore they shoot more accurately, further out.

 

[Java Man]

Maybe the larger and heavier balls just buck the wind/air currents better? Slower speeds might help maintain the path too.

Java Man