Rifling confusion

[Thunder14]

Well i need some education on rifling on a muzzleloader.I have a T/C Hawken 50cal shallow rifling.i can not see for the life of me how much effect the rifling is having on a patched round ball.I bench shoot a lot of 22cal and 223 so i understand bullet weight and rifling on a cartridge bullet. I am new to flintlocks.To me trying to riffle a patch seems counter productive because of the drag and a uniformed thickness and size of a patch when fired.So for the amount of spin a round ball gets I think is minimal to stabilize at any distance.As I am far from knowing anything but the basics at the moment so please educate me on this I want to learn as much as I can.

 

[rmark]

A TC Hawken flintlock .50 will have a 1-48 twist factory barrel with grooves .004 deep if I recall correctly. It should shoot from a .490 patched round ball up to about a 300 grain greased maxi type bullet. A pure round ball gun will often have deeper grooves and a slower twist (say 1-60), a pure bullet gun shallow grooves and a faster twist (say 1-21). So while the TC grooves and twist rate may be viewed as a bit of a compromise, at typical blackpowder velocities (say 1200 fps)it works fine.

Your .223 likely has about a 1-7 to 1-10 twist and about 3000 fps velocity, a lighter 55 grain bullet working well in the 1-10, a heavier and longer 70 grain bullet needs the 1-7 twist to stabilize.

A round ball is a short bullet for its diameter and can be stabilized by the slow twist.

 

[Zonie]

The patch does several things to make a rifle shoot better at long distances than a smoothbore would if it was shooting a ball.

First, the patch seals the gap between the ball and the bore and rifling to keep most of the powder gas behind the ball.

A patch of the right thickness also engages the rifling grooves and tightly grips the ball.
This causes the rifling to spin the ball as it is fired.

As rmark noted, round balls are very short so they don't require a lot of spin to stabilize them and keep them on course.

The 1:48 twist your TC has, has been proven to stabilize some of the shorter elongated bullets people use in their muzzleloaders. It is more than fast enough to stabilize a ball.
In fact, many of the barrels made for shooting roundballs actually have much slower twists than your TC has. A twist rate of 1:60 or slower has proven to be exceptionally accurate when shooting a patched roundball.

I mentioned shooting balls out of a smoothbore earlier.
This can be done with pretty good accuracy out to about 50 yards but beyond that, there's no telling where the ball will go.

Rifles shooting patched balls on the other hand will shoot very accuretly out to beyond 100 yards.

Good target shooters can shoot groups at 100 yards of less than 3 inches using iron sights.

 

[excess650]

A patched roundball will have impression of the patch all around its circunference, so the patch is effectively the "jacket". Even if the ball/patch fit isn't really tight when initially loaded, a greased patch will lessen blowby and the sudden pressure spike from blackpowder will cause the ball to "bump", or obuturate and increase the tightness in the bore. A roundball doesn't need much in the way of "twist" to keep it stable in that it is a sphere. A little bit of twist keeps it flying off like a knuckleball. Forsyth rifling might be twisted as slow as 1 turn in 144 inches, and it was intended specifically for roundballs.

Lead bullets launched with blackpowder will also "bump" up to groove diameter. The paper patched bullets used prior to the advent of jacketed bullets were often BORE diameter when patched and dependent upon the quick acceleration/pressure spike of the blackpowder to fill the grooves. A conical bullet needs more twist to keep it stable.

Jacketed bullets and smokeles powder are completely different animals, so don't even bother trying to equate them.

 

[Thunder14]

Thank everyone for helping me understand how the round ball and patch work in riffleing.

 

[Thunder14]

I just started making my own patches so I went to the fabric store with my wife the other day she is a seamstress so she knows a lot about fabrics so she picked me out 100% Cotten ticking pillow and mattress she says there is a difference so i will be trying to find out which one works best ,I have been very successful in making my own patch lube a lot of trial and adjusting so hopefully it will all come together. Once again thank you for you help.

 

[MSW]

one of the fun parts of muzzle loading is that you are in charge of your load's various components: the thickness of the patch, the patching material, the type and consistency of the patch lube, the diameter of the ball and the amount of powder used to propel the whole mess downrange.

each particular gun has a 'sweet spot,' where all these variables come into tune. (all rifles are, at the end of the day, resonant mechanism: they requite tuning, just as you would tune a piano or an internal combustion engine).


as a general rule, if you have a higher rate of twist, the zone of the sweet spot is narrower, thus:

in my one in 48 twist Thompson Center, if I vary the powder load weight by five grains, I will start to open up the group noticeably. However, in my Colerain 1:60, I can get away with a ten or twelve grain variance before things start to get sloppy. (remember that this is a volumetric measure, by the way)

I don't know why this is, but it is.

Other points to ponder: all guns have their own unique 'best load.' I doesn't matter is it's the same caliber, the same manufacturer, the same powder, ball, patch and so on... you have to work up a load for each of your guns.

For the best way to do this, I recommend Dutch Schoultz' method. This is far and away the best shooting accessory you can buy without a permit. here's a link:
http://blackpowderrifleaccuracy.com/


good luck in your quest for tiny groups, and
Make Good Smoke

 

[Thunder14]

I have spent quite a bit of time experimenting with different powder amounts and types 3f /2F i have found a good load at 50 yards open sight I have a real tight pattern when my eyes cooperate I can get a good cloverleaf I am very pleased with the consistency of the rifle but like you said it’s basically up to the loads you come up with,I was on the fence about ordering the Dutch Schultz book but for $20 what the heck. Thanks for your input I really appreciate everybody’s help.

 

[Dr5x]

I agree, MSW says what you need to consider probably a bit better than I do do
When teaching at the University I occasionally would come across a student who taught me a few things I wash;t expecting.
That is why I asked MSW to proof my book to spot any stupidities and see if any words were spelled correctly
Of any of yyou had two different girl friends in your distant youth you probably didn't them both the same way.
Your rifle is like one of those girls. You have to learn what lt likes
His pointing out that two rifles of the same caliber from even the same manufacturer might well require different treatments to achieve the desired result
Once you get everything, every variable nailed down, It doesn't need to take a long time,, you'll never let that rifle get away from you.
I don't think anyone will ever sell or give away an accurate rifle except in a case of advanced age or failing vision.

Giving my rifles to my grandson was one of the sadest days in my life.

Dutch Schoultz

 

[Dr5x]

Let me butt in here.
An elongated projectile has a greater amount of surface engaginging the rifling and can withstand a a more rapid twist.
A round ball when short started has only a very narrow belt around the ball engaging the rifling through the patch material and this very narrow belt would be ripped off in a quick twist barrel and would lose all the advantage of the e rifling
I think the round ball would respond nicely to a quicker spin but the nature of soft lead just won't let that happen

Dutch

 

[mooman76]

Very good info here. I might add that minies like shallow rifling better than a deep rifling. Easier to fill shallow rifling grooves than deeper. Every gun is its own and no one thing works best in all guns and something that doesn't work in one, may work in another.

 

[MSW]

I agree, MSW says what you need to consider probably a bit better than I do do
When teaching at the University I occasionally would come across a student who taught me a few things I wash;t expecting.
That is why I asked MSW to proof my book to spot any stupidities and see if any words were spelled correctly
Of any of yyou had two different girl friends in your distant youth you probably didn't them both the same way.
Your rifle is like one of those girls. You have to learn what lt likes
His pointing out that two rifles of the same caliber from even the same manufacturer might well require different treatments to achieve the desired result
Once you get everything, every variable nailed down, It doesn't need to take a long time,, you'll never let that rifle get away from you.
I don't think anyone will ever sell or give away an accurate rifle except in a case of advanced age or failing vision.

Giving my rifles to my grandson was one of the sadest days in my life.

Dutch Schoultz

emphasis added


it need not take a long time unless, of course, you enjoy tinkering with things or you feel the compelling need to buy a zillion gadgets and what-have-you thingies


(this message brought to you by the Gadget and What-Have-You Manufacturing Association)


as regards Dutch's assertion that I can spel gud ”¦ this is not so, but I appreciate the condiment anyway.

:haha:

 

[Vaino]

Don't think that a PRB will "bump" or expand as you put it....and further obturate the bore. BP pressures are low and the inertia of the PRB isn't sufficient to supply enough resistance for it to expand.

Certain conicals are said to expand and the MaxiBalls w/ their grooves and narrow rings are supposed to do that. The inertia of a heavier conical causes a greater pressure "spike" to occur and pushes the smaller dias into the rings thereby causing them to expand. Don't really know if this is an advertising ploy or reality. Certainly sounds better than saying a Buffalo Bullet expands.

A Minie Ball is different....its thin skirt expands into the grooves and onto the lands and obturates the bore. Minie Balls are purposely made undersize to facilitate loading when the bore is fouled by many shots while in battle.

My TC Hawken w/ its 1:48 twist is very accurate w/ a PRB and has at times head hit many squirrels.

The MaxiBalls w/ big powder charges leaded up the bore so that the lands were hard to see.....this was caused from the MaxiBall trying to go straight and not follow the rifling. This only occurred w/ the big charges.....Fred

 

[Dr5x]

I may have mentioned this before. An early subscriber immediately fastened on to the idea of using only compressed measurements of shooting patch cloth and soon was appearing at various shoots, spotted folk with the open groups of too thin a shooting patch and would in aa few moments measure their existing patch cloth, make a few adjustments by replacing their cloth with some of his and amazed the shooter with the great improvement in their groups and he would then move on to someone else.
I had lent a number of great books to him but they were lost when he died of some quick ampul illness.

Once you have worked up one rifle, it is much easier to work up another.
IT Does Not Have to Take a LONG TIME>

Dutch

 

[William O.]

I just started making my own patches so I went to the fabric store with my wife the other day she is a seamstress so she knows a lot about fabrics so she picked me out 100% Cotten ticking pillow and mattress she says there is a difference so i will be trying to find out which one works best ,I have been very successful in making my own patch lube a lot of trial and adjusting so hopefully it will all come together. Once again thank you for you help.

A quick word about fabric for patching, at least how it is around here. I've found that at the local fabric store there are two kinds of ticking; pillow ticking which is not 100% cotton and mattress ticking which is. Both appear to have a tight weave but the all cotton is tighter. Be sure to wash the sizing out before using. Also, while at the store, pick up some cotton flannel. It comes in white and it makes the best swabbing and cleaning patches I've yet found, plus one yard will last for years.

 

[excess650]

The fabric content is usually marked on the label on the bolt. I was at JoAnn Fabric last week and took my micrometer along. While looking for cotton canvas/cotton duck cloth, I ran across linen. The few thicker samples I measured were .012". Back to the cotton duck....the various "colors" measured .020" while the "natural" measured .025". Looking at their website, they (JoAnn's) have all of the cotton duck listed as the same weight, but obviously not the case.

In bores where I've had some cutting or burning of .018" pillow ticking, I've NEVER had the same with .025" cotton duck.

 

[Loyalist Dave]

That's an interesting tip..., I'll have to check that out.

LD

 

[Kansas Jake]

Pillow ticking can be found that is 100% cotton. I've use both pillow and mattress ticking. Try both and use the one that works best in your gun. The pillow ticking will be thinner than the mattress ticking.

 

[billraby]

I have a barrel with 104" twist. The ball is spinning at 11,400 rpm when it comes out. That is pretty fast and 104" twist is about the lowest you are going to get. Does not take much to stabilize a round ball. How many rpm does a football spin at when it is thrown?

 

[Rifleman1776]

I have a barrel with 104" twist.

We tend to get hung up a lot on numbers about twist, energy, velocity, etc. There is some value in making comparisons but getting out and burning powder is the only way to find what your rifle likes. There are some 144" twist barrels out there and have been since the early days of ml history. But, understand, accurate slow twist loads require a lot more powder. If that 104" twist barrel is larger than about .50 cal. methinks the butt end of the rifle gets almost as much punishment as from the business end. DAMHIK :shocked2: