Not being a smoothbore shooter I was not familiar with "dimpling" round balls to improve flight stability. Does anyone actually do that? Here is a gadget to automate the process:
http://www.forth-armoury.com/instructions-for-using-the-vortex-ball-roller.html
Never seen that thing. But my rock tumbler filled with round balls and run for a couple of hours does a pretty good job of rounding out the spruce and mold lines.
Doug
[hmm] Kinda makes since ...i guess... aint that why golf balls are dimpled...to fly further...
I achieve the same result using two worn out shoeing rasps.
Not worth the effort unless you just tumble them. That is easy.
Does either way make a noticable difference in accuracy?
This has been tested and verified; as far as golf balls go. However, it was pointed out that the golf club or iron imparts not only a spin on the ball but an angle (of attack) as well. Think of either a slice or a hook; both are caused by the angle at which they come off the club as well as the side ward spin they have. A pitcher's curve ball is the same only it's the spin put on the ball but instead of dimples it the stitching of the leather cover that cause the air flow to pull the ball into a curve. With a smooth bore there is no spin imparted to the ball so it zips along in a sort of wobble until it slows enough to impact the ground or what you were aiming at. A spinning ball is much more stable and will retain it's velocity longer in the same amount of time.
The way I shoot just leaving the powder out wouldn't make much difference. rdfce
Quote from: William on January 28, 2018
A spinning ball is much more stable and will retain it's velocity longer in the same amount of time.
That brought up something that got me to thinking, which could hazardous. How much spin does a patched roundball get from 1/60 twist rifling? And since it seems that more spin would be more stabilization for the ball, Why is it that a patched round ball in a fast twist rifling is not as accurate as slow twist rifling?
Next, is it better to shoot a patched roundball in fast twist rifling, after thorough experimenting with different powder charges?
If so, Why do we mostly shoot patched round ball with rifling from 1/45 thru 1/70?
Quote from: Fredredcj on January 26, 2018
Does either way make a noticable difference in accuracy?
Yes, accuracy is awful. The only up side is that I can shoot bare ball, think woods walk. Short range, 35 yds. it's ok. I have no plans to make any more.
I never thought about the possibility of shooting it unpatched. I wondered why anyone would want to put lube between the patch and ball.
Sometimes wonder if i will ever be smarter than an oyster hdslp
Quote from: pilgrim on January 28, 2018
Quote from: William on January 28, 2018
A spinning ball is much more stable and will retain it's velocity longer in the same amount of time.
That brought up something that got me to thinking, which could hazardous. How much spin does a patched roundball get from 1/60 twist rifling? And since it seems that more spin would be more stabilization for the ball, Why is it that a patched round ball in a fast twist rifling is not as accurate as slow twist rifling?
Next, is it better to shoot a patched roundball in fast twist rifling, after thorough experimenting with different powder charges?
If so, Why do we mostly shoot patched round ball with rifling from 1/45 thru 1/70?
The depth of the rifling has more to do with spinning and stabilizing a PRB than the twist rate. My old Lyman Great Plains Hunter barrel had a fast twist of 1/32 IIRC but very shallow rifling compared to my GP rifle barrel, 1/60. Also, a patched ball doesn't have much bearing surface in contact with the rifling either but being round it doesn't take much to get it spinning. Plus, if you try to spin the RB too fast, that small bearing surface is liable to get shoved past the lands and "skip" down the barrel.
Anyway, after checking out the dimpling tool, I don't think that they are implying that you can now get rifle accuracy from your smoothbore. The dimples are raised from the surface of the RB and upon loading a PRB the dimples crush down where the bearing surface is and where the patch contacts the rifling. I can see why this might improve accuracy but I would have to see the test results before I'd be completely sold on the system.
muzzleloader magazine had an article on "dimpled " balls this past year , forget which issue it`s in , but I have it laying around her somewhere !
Quote from: pilgrim on January 28, 2018
Quote from: William on January 28, 2018
A spinning ball is much more stable and will retain it's velocity longer in the same amount of time.
That brought up something that got me to thinking, which could hazardous. How much spin does a patched roundball get from 1/60 twist rifling? And since it seems that more spin would be more stabilization for the ball, Why is it that a patched round ball in a fast twist rifling is not as accurate as slow twist rifling?
Next, is it better to shoot a patched roundball in fast twist rifling, after thorough experimenting with different powder charges?
If so, Why do we mostly shoot patched round ball with rifling from 1/45 thru 1/70?
William is absolutely correct concerning rifle twist & groove depth. Faster rot gives excellent accuracy if the grooves are deep enough, say .006" on the low side to the .016" radius grooves used in Rice barrels. Even with .006" grooves, a slightly slower twist works better. Back in the day, 1-48" was a common rot regardless of caliber.
Think of it this way. The only contact an undersized round ball has with the rifling is around it's diameter and that is through the patching material. So, the patch has two main jobs; seal the hot gasses from getting around the ball as well as to grip the ball by a very thin ring and spin the ball according to the twist rate of the rifling. Too much powder and the patch gets cut or burns through. Rifling adds resistance to moving the PRB out of the barrel and we need a certain amount of it in in order to get consistent accuracy. However, too much resistance or too much speed and the thin ring that is formed between the rifling and patch is overcome, at least for a moment and the PRB is shoved past the rifling without turning or starting to spin. It is like throwing a football and at some point in the throw your hand slips for just a split second. It's going to give you different results than you were planning on.
At least that is how I imagine this to be taking place. One last thing; I know that folks have gotten good accuracy shooting PRB out of fast twist barrels by keeping the velocity low. 20-40 grains in a .54, that sort of charge reduction. I've also seen some really big bore rifles that have what seems to be ridiculously slow twist rates. 1/110, 1/107, etc. So that would lead me to believe that caliber / bore size fits into all this somewhere.
I have no intention of derailing bmtshooter's post/topic, so I will start a new topic.
I did that for you! hi:
~WH~