Smoothbore accuracy with different barrel lengths

[Jim Wimbish, 10395]

Has anyone done any testing with smoothbores to determine how accuracy is affected by barrel length? I have heard that the 42 inch barrels are the most accurate. But I have not heard that anyone has actually tested the 24, 30, 34, and 36 inch barrels to see how much accuracy is lost as the barrels get shorter. From what I understand, the balls actually roll out of the barrel and knurling the ball is important for the shorter barrels to get the ball rolling as quickly as possible. Also, the ball should be as round as possible for best accuracy, with all traces of the sprue removed. Since there is no rifling in the bore, consistent high quality roundballs are essential for best accuracy.

[Curt]

Hallo!

No real testing.

I suspect one has to do what, IIRC, Lyman did years ago when they took a gun and kept reducing the barrel length to ascertain performance. :) :)

I do have experience in shooting sundry smoothbores with 36, 38, 42, 44, and 46 inch barrels. Sighted and unsighted. 12, 20, 24, and 30 gauge.

My only observation is personal. A .75 Long Land Pattern musket weighing 14 pounds is its own interesting beast off-hand. But, in brief and in general... for me... the shorter guns were a mix. Meaning, the lighter weight meant greater 'control' or steadiness in the shooting,, but the shorter "sight radius' translated any movement or flinching into pulling terh gun off center target much more easily.

And that is also a variable of what was being shot and how. For example, for competition, a pard and I took on a team of six. We lost the match by a fraction of a point on a string measurement, but Rich's musket's frizzen died and he was unable to fire 2/3rd's of the way through.
Part of our secret was that we were both using .735 round ball paper cartridges, while the competition was using either .715 in their .75's or .67 in their .69's. Better shots aside. :)
Using an N-SSA style say vinyl tube and a naked ball is a complication.

Of course, others' mileage will vary...

Curt

[jonk]

Just my opinion here...

Longer barrels are more accurate for two reasons; first the longer sight radius allows the eye to center the front sight- usually the only sight except for some 1816s and Potsdams- more easily; second, the longer barrel does permit longer bore to bullet contact, for whatever it is worth.

I don't think knurling the ball does anything, other than allow it to carry more lube and foul less.

I am on the fence about the sprue. On one hand, removing it means a more uniform ball. On the other hand, seating the sprue centered and down allows some rearward drag stabilization- I strongly suspect that on firing, the sprue aligns to the base anyhow.

I think the biggest two detriments to accuracy are balls that are too loose (you really need to measure the bore) and the challenge of the lack of a rear sight- except for those that are sighted, of course. The former being the worst, you can get used to the second.

[John Holland]

I believe it may have been Turner Kirkland/Dixie Gun Works who did the test on shortening the barrel v.s performance regarding powder burn, velocity, etc. Yes, I should get out an old Dixie catalogue to check, but they are buried deep in the archives......very deep!
JDH

[Rich Foster]

John, You posted almost my exact words when i was signing to post. Good thing I looked before writitng this post. Hope you find the article. I will elaborate a little more. Stability and velocity is what you want to achieve to make a gun accurate. Of course back in the 1840's they did not have all this electronic we have today. All I can say is who ever was given credit for designing the M1842 was not a average Joe. It is probablly the most balance musket design and lasted until repeating arms came of age. I am in the process of building a 36" 42' cut down and I will post results from it. I have built a number of 42" barrels and they are very accurate. I am very interested myself. I don't see that there will be much difference at 25yds but 50yds will tell you how well you can tuned a shorter barrel smoothy. Rich

[Jim Wimbish, 10395]

Rich,

I will be very interested to see what comes out of your testing.