Putting backspin on a smoothbore roundball

[Pierce]

I may have found a potentially very accurate way to load a smoothbore flintlock. The idea came from how a goofball has backspin on it to help it fly longer and straighter. So I guess in my mind I was trying to think of a way to put backspin on a roundball as it leaves tge muzzle of a smoothbore. So I figured that if you want the ball to spin in a set direction you need uneven pressure and friction around the ball. So I though okay maybe if I fold my patch in half and  put it on the bottom side of the barrel. Leaving the roundball touching the barrel on the top side but touching the patch on the bottom side. I figured that since the patch would have less friction relative to the lead on the barrel it would kick the ball into a backspin. Sure enough, when I loaded my gun with 160 grains of powder in that way I shot my best group at 50 yards being a 2" group. And at 100 yards an 8" group! I have never gotten groups that good out of that gun. So I am not sure if this is some weird fluke or not but it would be cool to see what other people's experiences are with this loading technique for a smoothbore.   I'll ad a picture showing how I loaded it since it is difficult to describe in few words.

[New Fowler]

What caliber is your smoothie, thats a massive barrel

[Pierce]

It is a 50 cal. I use a .454 ball tho and double patch of pillow ticking. The .490 ball fits in there a little too perfectly to use a patch and I couldn't find a bullet mold for a .480 roundball. So .454 ball is what I use which also fits in my remington new model army perfectly as well. But this is the flintlock I made out of hardware store materials. The barrel is.5in drawn over mandrel tubing with .25in walls. It's a bit over kill but I'd rather it be over kill than under kill and have it kill me haha.

[Dutch]

Rich,
A golf ball goes further with a hook spin (and forward roll out) not necessarily more accurately with backspin.  Concentric spin makes the ball more accurate (rifling) so…
Just a suggestion - try the patch at 12 o’clock in lieu of 6 o’clock and report your results, I’m just curious.
Another thought a golf ball has dimples to help stabilize it in the air, I’ve never shot a dimpled round ball but that might be an idea for round three of the trials

[Pierce]

I did try it at 12 o'clock and it hit the ground  before it got to my target. It was hitting wayyyyy low. The spining creates lift and I figured the reason it hit the ground is because it created high pressure above the ball and low pressure bellow the ball, essentially sucking it to the ground. I didnt try just aiming way high to compensate..maybe it would technically group better tho, i will have to give that a try. And I'm not exactly sure why in my case it worked good with backspin. I am guessing the added lift flattened out the arch more making it flatter for longer. 

But it makes sense that having forward spin would make it fly straighter because when you take a glider and throw it upside down, while it goes to the ground much more quickly it fly straighter. I am assuming that that is because the "lift" is essentially above the center of gravity giving it 3 forces of balance; high center of gravity, gravity, and downward lift.

[smylee grouch]

One of my late shooting buddies claimed he could do that by altering the crown on one side   

[Pierce]

Haha I am skeptical of the spru being used to throw a ball into a favorable spin would work...maybe tho!!

Anyway here is a drawing of what I was trying to say

[New Fowler]

Rich,
A golf ball goes further with a hook spin (and forward roll out) not necessarily more accurately with backspin.  Concentric spin makes the ball more accurate (rifling) so…
Just a suggestion - try the patch at 12 o’clock in lieu of 6 o’clock and report your results, I’m just curious.
Another thought a golf ball has dimples to help stabilize it in the air, I’ve never shot a dimpled round ball but that might be an idea for round three of the trials

I have found dimpled round balls don't do well at the velocities most people want out of a hunting gun. Historically, chewed balls were shot unmatched, and the idea was to raise fingers of lead that hold the ball in the bore like a patch. At lighter powder charges/lower velocity, the dimples may do something, but they didn't work for me with the charges I shoot.

[Pierce]

Was that from a smoothbore? Also I had the same experience with my chewed balls when I shot without any spin on them. I had like 1 foot groups at 50 yards which is pretty bad. But I think with the added predictable spin it might work to stabilize it because it is spining in a predictable way. Im gonna cast up some balls this morning and rough some of them up and try shooting with topspin but aiming higher to compensate for the drop to see if the groups are better and I am also going to try those chewed balls

[Daryl]

With the lead ball being pressed against the upper bore wall, how much leading do you get?

[New Fowler]

Was that from a smoothbore? Also I had the same experience with my chewed balls when I shot without any spin on them. I had like 1 foot groups at 50 yards which is pretty bad. But I think with the added predictable spin it might work to stabilize it because it is spining in a predictable way. Im gonna cast up some balls this morning and rough some of them up and try shooting with topspin but aiming higher to compensate for the drop to see if the groups are better and I am also going to try those chewed balls

Yes from a smooth bore. tried it with 80-120 grains of 2f, groups were 3-6 inches at 25 yards. Bare balls run around 2-3 inches. My bore is tapered heavily in the middle, patched balls do not work for me at all. They either burn up, or load so tight I can't load them with the wooden ramrod.

[Tumbledown]

I am willing to bet the ball hit the ground not from spin but from the gasses exerting lopsided pressure on the ball due to the offset patch.

[Pierce]

I am willing to bet the ball hit the ground not from spin but from the gasses exerting lopsided pressure on the ball due to the offset patch.

Maybe! I really dont know, it may not even actually work haha could have just been that my projectile had an optimal amount of pressure for that barrel.
But on the point of leading i havent really had any leading surprisingly! Smooth as ever. What is really wanna do is turn it into a rifle. Add rifling. Thats the ideal of course. I just dont really know how to do it

[Daryl]

You could scratch-rifle it for better round ball accuracy with something like 40 grit paper or emery, but that might only work with snug loads, needed to keep the scratch rifling clean.

[Pierce]

You could scratch-rifle it for better round ball accuracy with something like 40 grit paper or emery, but that might only work with snug loads, needed to keep the scratch rifling clean.

Okay now this is a cool idea! I use a very tight patch anyway. I want more info on this! This is a cool idea

[Daryl]

ALR member here, Dphar noted that years ago, a couple guys in the Northern USA used to win all the smoothbore round ball shoots at rendezvous and the reason was they had
scratch-rifled their bores. Tight fit of paper on a jag, twist as you push down and pull it out, time after time. Done deal.
That's how you do it if you just want to put in some scratches. With a minor amount of skill, you can be quite accurate in your twisting. Don't make it to fast, just a slow 1/2 turn
the length of the barrel (if 40" or so in length) would help in the accuracy department. Less than 1/2 turn if shorter than 40", I would suggest.

[Pierce]

ALR member here, Dphar noted that years ago, a couple guys in the Northern USA used to win all the smoothbore round ball shoots at rendezvous and the reason was they had
scratch-rifled their bores. Tight fit of paper on a jag, twist as you push down and pull it out, time after time. Done deal.
That's how you do it if you just want to put in some scratches. With a minor amount of skill, you can be quite accurate in your twisting. Don't make it to fast, just a slow 1/2 turn
the length of the barrel (if 40" or so in length) would help in the accuracy department. Less than 1/2 turn if shorter than 40", I would suggest.

Do you have to do light loads for it to work or does a tight fitting patch make heavier loads work too?

[Pierce]

Okay okay this scratch-rifling us actually showing some promise. My ramrod spins on its own when I put a cleaning patch through it. I will admit I was very skeptical but it is showing some promise. I've just gotta shoot it now haha

[Daryl]

Whether light loads need to be used, or not, depends on your combination & your gun.
Any amount of spin should help, but it needs to be consistent, shot to shot.
The cleaner your combination leaves the bore, the better the 'scratch rifling' will work.
With a short barrel, I should possibly have noted, a 1/4 turn might be best.
I should note, I have never done this myself, however, it's all physics.

[alacran]

Could it be that the DOM pipe is not straight and you need the heavy loads just to get the balls to get there. Those are loads one would use in a Brown Bess or other large bore muskets. There may be some here that shoot the sighted smoothbore matches at Friendship who might opine on what a .50cal. smoothbore load should be. I'm willing to bet that the loads would be less than 80 grains of 2F.
I think you may be over thinking it.

[Pierce]

Could it be that the DOM pipe is not straight and you need the heavy loads just to get the balls to get there. Those are loads one would use in a Brown Bess or other large bore muskets. There may be some here that shoot the sighted smoothbore matches at Friendship who might opine on what a .50cal. smoothbore load should be. I'm willing to bet that the loads would be less than 80 grains of 2F.
I think you may be over thinking it.

No its straight. It shoots 3 inch groups at 50 yards with 90 grains of powder. It's just that when shooting at 100 yards the ball drops so much abs loses so much velocity that it goes everywhere when using 90 grains. Since it has no spin that rapid decrease in velocity allows the imperfections in the roundball to take over. The idea behind the double loads is to flatten out the arch and maintain the higher velocity at those further distances. And it works. I normally get 12" groups at 100 yards with the 180 grain loads.

Anyway I figured out a pretty cool way to get rifling in the barrel. I did the scratch rifling and that actually worked but I read that it only lasts for 150 shots or so. So I wanted to make deep grooves. I figured that since the ramrod rotated on its own when there was a tight cleaning patch that I could get consistent grooves if I put a little metal chisle on the side of the ram rod and build up the other side of the ramrod to push the chisle into the barrel as I pushed it down. And sure enough, it worked! That scratch rifling guided the chisle into perfect rifling grooves and then just did it a couple more times to make the groves deeper and make more of them. So now I've got micro grove rifling haha, super cool!

[Daryl]

Where there is a will, there is a way.

180gr. imho, is WAY too much powder for a .50, especially one made with tubing for a barrel.

[Pierce]

Where there is a will, there is a way.

180gr. imho, is WAY too much powder for a .50, especially one made with tubing for a barrel.

Well hopefully with the new rifling I can lower the powder charge and get good groups at 100 yards. It is also homemade blackpowder so likely less powerful than others. However, it is compressed and corned.

But anyway I threw a lighted nock down the barrel to try and get some photos of the rifling but it is tough with my phone camera. I'll post the photos anyway tho. It was very windy today, 30 mph winds, so I didnt get a chance to shoot it to test it out. Hopefully it wont be windy tomorrow and ill give it a go. I'll of course have to restart my load to find what works best but I will let you guys know my results when I get them!

[Daryl]

Well done. Nothing like taking an adventure and having it coming out well.

[HighUintas]

This is a really interesting thread. I hope your micro rifling works. I'm excited to see the results.