Dimpled balls again

[Grandpa Ron]

A recent article in Muzzleblast points out the conundrum of shooting a smoothbore.

The author describes switching from a patched round ball to a ball with the sprew removed and the surface stippled on a rasp. If I read correctly the ball was loaded with no patch (bare ball) directly on the powder and his group improved considerably.

I have tested various loads, including patched balls, wads and balls and even bare balls on powder. My results from the bench at forty yards showed very little difference. Most would group the majority of the balls in an 8” circle.

If I understand correctly, the author was using a .715 ball with 48 grains of 3F powder. This is about 2/3 of my 28 ga. load.

Since I have no reason to doubt the authors results; it think it points out the fickle nature of smoothbore shooting.

I was curious if anyone had actually tested a rough surface ball. It is on my to-do list when the weather breaks.

 

[crockett]

I have not. Years ago when the Bevel Brothers had a column they did some testing of dimpled vs non-dimpled and claimed in a smooth bore, no spin to the ball, the dimple "flew" more straight but I cannot recall if it was enough of an improvement to be worthwhile dimpling the ball. It's why golf balls are dimpled.
BTW, on the Hevi-shot, those pellets have a little nub and it is supposed to work like a badminton **** in flying straighter, giving a better pattern. I always wondered whether an old style ball with a sprue would not be a similar situation when shot from a smoothbore.

 

[Rifleman1776]

Dimpled balls are but one notion that smoothies can give improved accuracty with tinkering. Putting tails on them is another. Fiddle all you want, you might discover something amazing. Do wat works for you.

 

[Billnpatti]

A couple of years ago, I ran a test comparing .490 smooth balls to .490 balls having a "textured" surface. The texture was achieved by allowing the balls to tumble in a rock tumbler for approximately 8 hours. The texture resembled a sand blasted surface. This is a long way from an actual dimpled surface but the results are, none the less, interesting. All other factors were carefully controlled such that the only difference between the balls was textured VS smooth balls. The test consisted of shooting 5 targets at 50 yards with smooth balls and doing the same thing using the textured balls. Five shots on each target. The group sizes were measured for each target and the average for the five smooth ball targets was 1.238 inches with a std. dev. of 0.551. The average group size for the textured balls was 1.`150 with a std. dev. of 0.439. The textured balls appeared to yield a group size reduction of 7.11% with a std. dev. reduction of 20.33%. Meaningful? :idunno: You call it.

 

[FishDFly]

There are many thoughts on what it takes to make a smooth bore shoot its best.

One Texas smoothbore rifle shooter swears a hard ball shoots better than a pure lead ball. Do not know, I have yet to beat him. Seems, like an oversize ball without a patch would lead to leading.

Dimples go in, and pimples go out from the ball diameter.

Smoothbore pistol shooters will pimple a ball between a rasp and a very rough ******* fie. The rough ******* file makes it easier to get the ball across the rasp. Thought is the pimples allow the patch to grasp the ball and the ball is slightly over barrel size, increasing friction while in the barrel..

Another thing is smoothbore pistol shooters shoot about double the amount of powder than normal to get them to be accurate. I just bought a smoothbore and finished casting and dimpling the balls. It’s a 44 cal. and was told to start with about 40 grains of powder.

Many theories on smoothbores and what it takes to make them accurate.

 

[coloradoclyde]

A couple of years ago, I ran a test comparing .490 smooth balls to .490 balls having a "textured" surface. The texture was achieved by allowing the balls to tumble in a rock tumbler for approximately 8 hours. The texture resembled a sand blasted surface. This is a long way from an actual dimpled surface but the results are, none the less, interesting. All other factors were carefully controlled such that the only difference between the balls was textured VS smooth balls. The test consisted of shooting 5 targets at 50 yards with smooth balls and doing the same thing using the textured balls. Five shots on each target. The group sizes were measured for each target and the average for the five smooth ball targets was 1.238 inches with a std. dev. of 0.551. The average group size for the textured balls was 1.`150 with a std. dev. of 0.439. The textured balls appeared to yield a group size reduction of 7.11% with a std. dev. reduction of 20.33%. Meaningful? :idunno: You call it.

Were they patched, dimpled round ball in a rifle?

never thought to try that.

 

[Grandpa Ron]

I had a discussion with some of the top smoothbore shooter at the NMLRA Nationals in Friendship IN.

This is 50 yards, no rear sight, not set trigger and flintlock
.
The results were;
Ӣ Shooter #1, .54 cal. 70 grains 3F, dry wad, very tight canvas patch. Mallet to start ball.
Ӣ Shooter #2, .54 cal. 90 grains, granulation not recorded, ticking spit patch sloppy wet, tight ball fit but I do not believe a mallet was needed.
Ӣ Shooter #3, .60 cal. 90 grains, 3F, lubed patch, moderate ball pressure, could start with short starter.
Ӣ Shooter #4, my load, .54 cal. 70 grains 2F, lubed 3/8 cushion wad and moderately tight lubed patch and ball.
Ӣ There were several other loads but they were all variation on the above themes.

Like many I have come to the conclusion that there is no “secret” combination. You have to find what works for you. That may include dimpled balls, hard lead, wads and etc.

I have also reached the conclusion that these top shooters not only hold the sight alignment fixed thru the shot, there head and stock position is exactly the same shot after shot. In short these folks are really good shooters. :wink:

Please do not confuse this type of shooting with hunting or reenactment matches from the pouch. This is paper punching and trying to eek out the last bit of accuracy. Many of my fellow reenactors do just fine with historically documented loads, including bare ball on powder.

But they are not trying to hit a clay bird at 50 yards off hand every time.

 

[thatoneguy82]

Did tumbling the balls for that period reduce their diameter and what type of media did you tumble them in?

 

[Billnpatti]

Yep, they were patched with 100% cotton drill that was 0.018. My lube was Bore Butter. The balls were not truly dimpled, just textured with a finish similar to a sand blasted surface that used a coarse grade of sand, The textured surface was what resulted from the balls hitting together in the tumbler over an 8 hour period. The only thing in the tumbler were the balls, no tumbling medium of any kind.

 

[FishDFly]

"I have also reached the conclusion that these top shooters not only hold the sight alignment fixed thru the shot, there head and stock position is exactly the same shot after shot. In short these folks are really good shooters."


Consistency is what wins, there are no true secrets.

Tumbling originally started to remove the sprue from cast balls to make them look like swaged balls.

I do not think you can compact lead balls by tumbling.

 

[Billnpatti]

I tumbled 50 balls in the tumbler with no medium of any kind, only the balls. Before tumbling I measured each ball on three axis X, Y & Z making sure not to include the spru in any of the measurements. Before tumbling, the mean diameter for the 50 balls was 0.4880 with a std. dev. of 0.001. The high measurement was 0.4900 and the low was 0.4865. The extreme spread was 0.0035.

After tumbling, the balls were all measured again on three axis. The spru was no longer visable so it was not a factor in selecting the X,Y & Z axis. The mean diameter was 0.4897 with a std. dev. of 0.001 The high was 0.4972 and the low was 0.4864. The extreme spread was 0.0108.

In addition, I weighed each of the balls before and after tumbling to see if they lost any weight due to the tumbling. The mean weight prior to tumbling was `175.1 grains with a std. dev. of 0.52 grains. After tumbling the mean weight was 174.5 grains with a std. dev. of 0.54 grains. So, there was an average loss of 0.6 grains but the std. dev. remained pretty constant.

 

[Col. Batguano]

The M1 Abrams tank shoots from a 120mm smoothbore too, (albiet not shooting a roundball) and that is quite accurate at quite long ranges. Keep tinkering.

 

[matt denison]

"It's why golf balls are dimpled"

Golf balls are dimpled to fly farther, not more accurately. There are no sights on a golf club.

 

[matt denison]

"work like a badminton **** in flying straighter"

The feathered tail on a badmitten **** doesn't make it fly straighter, it slows the **** down enough that badmitten can be played on a relatively small area. It is difficult to hit a badmitten **** more than 30 feet.

 

[azmntman]

Theres a guy here been posting about his abilities....I'm betting he could smack it over 1oo yds with no issues? Course he advocates using smokless too :bull: ? Which will get ya KILLED on a bad day and just maimed if yer real lucky :idunno:

 

[satwel]

When I started shooting a smoothbore, I experimented with textured balls that I rolled between two rasps. I didn't see any difference in the consistency of my groups.

I wish I could remember where I once read that the US Ordnance Dept experimented with improving round ball accuracy somewhere around the 1830s or 1840s. Their conclusion was that round balls are most accurate when driven at either very low or very high velocities. Neither of which was practical from a shoulder fired infantry weapon.

 

[FishDFly]

"It's why golf balls are dimpled"

I thought they were dimpled to make them easier to pick up and get out of the water.

 

[George]

I sometimes tumble balls for my 20 ga. smoothbore, but not for purposes of accuracy, my accuracy is OK. I do it to eliminate the sprue so I can load the ball any whichaway without having to center the sprue. I do it by simply shaking the balls in a container for 20-30 minutes. Works well, and does what I want.





Spence

 

[coloradoclyde]

"It's why golf balls are dimpled"

Golf balls are dimpled to fly farther, not more accurately. There are no sights on a golf club.

Close ..but no cigar! check this out. http://www.golfdigest.com/blogs/the-loop/2014/12/this-is-what-it-looks-like-to.html

 

[azmntman]

I think it was our lovely Cynthia Lee? who suggested putting em all in a box in the trunk of yo auto and letting the pothole do the work? I have yet to try it (dimpling my balls) but may get to that point soon :hmm: