Some questions on "rate of twist" (rifling) and projectiles . . .

[bedbugbilly]

My interest has always been primarily shooting "round ball" - and I'm pretty "traditional" . . . i.e. not in to in-lines, saboted bullets, etc. In my general browsing "pastime" of looking at muzzleloaders, etc. - I got to thinking about "rate of twist" and have a couple of questions for anyone much wiser than I.

As an example - the Lyman Great Plains Rifle is available in either .50 or 54. Each is available with either a slow twist or a fast twist - i.e. 1 in 60" versus 1 in 32". I've always used slow twist rifle barrels on the guns I've made - Green Mountain, Rahl and many years ago a Numrich and even a Bill Large.

So my question is this - the 1 in 60" twist is intended for use with patched round ball - the faster twist of 1 in 32" for the conicals, etc. What effect or what would be the result if you use a patch roundball in a "faster twist" such as the 1 in 32"? If you used the same powder charge for both rb and a conical type - does one increase the internal barrel pressure over the other? Can both be accurate out of a fast twist rifling? Are the feet per second that both types of projectiles travel affected? Or . . . is it dangerouse to use a rb out of a fast twist barrel?

And I guess, the same inquiries in regards to using a conical type projectile out of a slow twist versus a rb?

As I said, my only experience has been with slow twist barrels intended for rb. I got to wondering though - as I read about the Lyman GP for example which is offered in both fast and slow twist - if one would be better over the other? If a person could only afford one rifle to hunt and shoot with - some states are rb hunting only (I think). So if they were interested in shooting both the conical type projectiles and rb - which twist would be the best for them to purchase? Or, is there a need for them to purchase a spare barrel so they have one in slow twist and one in fast twist?

I'm sure others have had these thoughts and questions as well so for those knowledgeable in the different barrel types - can you give us a little education on it? Thanks!

 

[Pahoo]

My Spin on projectiles

I'm sure others have had these thoughts and questions as well so for those knowledgeable in the different barrel types - can you give us a little education on it? Thanks!

Yes, this has been asked before and you will find a number of posts if you do a search. ...

If this question comes up during our basic class, I use the football and baseball analogy, to explain twist or as they say, "Spin" .....
What happens when a pitcher, throws hard and puts a lot of spin, on a hardball?
What happens to a football when the quarter back, again, throws hard and puts a lot of spin on the football?

Footballs are conicals and require spin to fly far and straight, to the target.
You can make a round-ball do crazy things with or without spin. ...

Now then you can shoot round-ball out of a faster twist if you load down. That is fine for paper but may not be for hunting......
You can shoot a conical out of a slow twist and it will likely tumble as it needs more spin.

Years ago TC and many others only came out with a faster twist on their traditionals. What a shame and most were 1:48 which "may" work but not great for either. That's when In-Line minds started butchering SideLock rifles in order to mount optics. I have a SideLock that use to cary a laser.

Be Safe !!!

 

[mykeal]

The only issue that arises from using a slow twist barrel with conicals or a fast twist barrel with round balls is whether the round is stabilized.

Round balls need the slower twist rate to stabilize; if fired from a fast twist barrel at the velocity (thus powder charge) normally used with a slow twist barrel they will over-rotate and not be stable in flight. Note that this is a general statement; the actual result depends on the ball size, twist rate of the barrel, amount of powder, type of lube and other factors. It is possible to get a stable round ball out of a fast twist if the powder charge is reduced, thus lowering the velocity. It will take some experimenting to find the right combination.

A similar argument applies to conicals - they need the faster twist rate to stabilize at 'normal' velocities. As far as I know, however, it's not generally successful to increase the powder charge (and thus velocity) in a slow twist barrel using a conical. One probably reaches the point where additional powder has little effect in increasing velocity before the round stabilizes.

It is not dangerous to mix round balls with fast twist barrels or conicals with slow twist barrels; it just affects accuracy.

 

[Pahoo]

Pushing a round ball, too hard.

they will over-rotate and not be stable in flight.

True or they may even start "skipping" or sliding over the rifling, again, on how hard you push them. ...

Be Safe !!!

 

[Captchee]

As others have alluded to , there are many views on this .
The basic modern theory however is that a RB needs a slow twist and a conical a fast twist .
However . There is more to it then that .
Lets take a RB . If a we study Forsyth alittle bit , what he said in so many words is that the twist rate for a RB is dictated by the size of the ball . IE a 36 cal ball needs more spin then a 62 cal ball . Basically the reason is one of mass . In that a larger sphere will maintain its rotation much easier then a smaller sphere . As such a smaller sphere needs more spin in order to maintain that spin over a long distance .

Conical on the other hand differ because of their shape . As the shape changes so does their reaction to the rate of twist .
Case in point . In my 54 cal long rifle I have a 1 in 70 twist . When hunting up in the canyons for elk , I use a 435grain Bernard Minie . That conical with a 110 grain charge of 3F will place round after round in a paper plate at 100 yards . At 50 yards it holds a 3 inch group . If I use say a TC maxie ball or a standard 54 cal Minie , im lucky to keep it on the paper
While not as good as a PRB out of the same barrel , its very effective and consistently will place the conical in the kill zone .

Now lets look at say the 1853 Enfield. Hands down a dedicated conical gun . Yet its original twist rate was 1 in 120 later it was sped up to 1 in 78 . Which is far slower then what is acceptable today yet its effective range is still way , way out there .
the 1863 rem (Zouave) had if i reall a 1 in 60 rate of twist and also was very accurate with a conical at long range .
So how can that be .
Well it’s the type of rifling , rate of twist and the conical which complement each other well .
So can you shoot a conical out of a slow twist , YES , the better the conical design compliments the rifling and twist rate , the better it will stabilize

Can you shoot a RB out of a fast twist , ,, yes but as the others have said , normally you need to low the ball down so that it doesn’t strip the rifling or shoot a small enough ball that it complements the twist rate .
Its all a give an take

 

[Old Stony]

TC's Hawkens have a 1:48 barrel, which is a compromise. It will shoot either conical or RB, and do a fair job of either, but not the best that can be done with either. Pushing a fast round ball out of a fast twist barrel can result in torn patches occasionally and erratic performance. You are better off to use a differrent barrel for each type of bullet. I don't...and won't own an inline...but I doubt any of them have a slow enough twist to handle round balls with any success.

 

[Hawg]

The bigger the caliber the slower twist required to stabilize a conical. The P53 Enfield had a twist of 1:72 but fired either a PRB or more commonly a .577 caliber minie. The minie is hollow based almost to the center of the bullet giving it a weight forward profile closer to a round ball than a true conical. My .54 Sharps has a twist of 1:54 and fires a 490 grain conical.

 

[woodnbow]

Agree with pretty much everything above except

I doubt very much you could over rotate a round ball. If you could find a way to prevent stripping the rifling so that it had a consistent spin from shot to shot I'm pretty sure it would be as accurate as one shot from a slower rate of twist. Just my opinion and I have no way to verify it so that's all it is..

 

[Sure Shot Mc Gee]

My opinion:
We all know thru engineering. Slow twist-rates accommodate a particular projectile as does faster twist-rates prefer another. If common sense is used its so much easier to have two different barrels available for ones desire's. I have no intentions of compromising my slow twist-barrel with plastic sabot residue. Because of a sabots required need. For a higher charge of powder to stabilize it properly for its longer intended distances. Nor will I shoot a slight charge of powder to accommodate a patched balls mediocre accuracy from a fast twist-barrel and gaining nothing more than a 25-50 yard paper puncher. I can do that type of plinking with a 22 LR. All these B/P rifles have an intended purpose. To purposely deviate from a barrel manufactures advice is where someone gets into a bind of sorts somehow some way not expecting.

S/S

 

[Captchee]

some of the modern reproduction 1853 Enfield have a 1:72 twist but originals carried a 1:78 and prior to that a very slow 1: in 120 Maybe it was 1 : 102 , ill have to look it up . But as I recall , that was on the first model Pattern 1853 . Later models carried the 1:78
What was referred to as a ball load for the Enfield is most commonly associated with the Pritchett ball , which isn’t a round ball at all .
One could shoot a patched round ball . I have done it . But do to the shallow rifling ????
The Enfield also had progressive rifling . However today we consider progressive to mean that the rate of twist changes . that’s not the case with the Enfield which associated progressive with depth vs. twist rate .

While today we do think in terms of fast twist for conical , that was not always the case with a lot of the original designs carrying what we would consider very slow twists or RB twists . Even with that , the recorded accuracy with a big heavy conical being pushed what many today seem to think of as light loads (70-90 grains of black) produce very good long range accuracy .
Why someone would think they would need a sabot in such a rifle , is beyond me . But if that’s what a person is thinking of then ya , they would need a rifle that was suited for that

 

[Hawg]

some of the modern reproduction 1853 Enfield have a 1:72 twist but originals carried a 1:78

You're right and I even have an original P53 made in 61.

 

[bedbugbilly]

Thanks for your information all - greatly appreciated.

I may be wrong, but I don't think we can really compare the military Minie to the conicals that have been designed for these newer fast twist barrels - unless I am not clear as to what the conicals are that are being used in the faster twist side locks. Are they "nose heavy" with a hollow base/thin skirt like the traditional military "mine" or are they more of a solid base? I'm assuming the "sabots" that are used in a lot of these guns is what "grips" the rifling?

The original military minie is a thin skirted, nose heavy projectile. I've shot a lot of different rifled muskets - Enfield, 1855, '61, Remington 1863, Mississippi, etc. - .54 and .58. They of course all have slower twists and some of them have some very interesting slow twists - shallow rifling, etc. - I've found them all to be pretty accurate. Of course the minie has to be sized to the barrel to be accurate - if not, "key holing" is almost a certainty. I had a Remington 1862 "Zouave' that the barrel was getting shot out on and I can speak from experience on that one.!

A number of years ago, I was in a "long range" shoot/test up at Camp Grayling on the 1,000 meter range. It was surprising the accuracy of the various models were capable of - but the one surprising thing that came out of the shoot was that a Henry out shot us all. We were shooting at "pop up" targets that were about 2' X 3". Using standard service loads, most of us did pretty well up to about 600 meters. At 1,000 meters, we had a life size steel cut-out of a horse and the fellow shooting the Henry was able to make it ping about 80% of his shots - the rest of us didn't do so well.

As I said, I'm pretty much a "traditionalist" so it's kind of hard for me to think of putting a conical down anything but a rifled musket. I'm not saying it's wrong, I'm just saying that I am pretty set in my ways in using rb in a slow twist barrel on a traditional side lock. With all of the rifles being made out there with the fast twist or with a compromise of somewhere in between, I was interested in the pros and cons of using the two different projectile shapes in the same barrel - and the results, problems, etc. in how the different twists react to the two designs of projectiles.

Years ago (I'm talking in the '60's) one of the companies was making muzzleloading barrels with a "gain twist" - I believe it was Numrich but I might be wrong on that. Of course the theory was that the patched ball, as it progressed down the barrel picked up rotation speed which was supposed to give it more accuracy. I never had the chance to shoot one of those barrels but I can't see where it would be any advantage? The ball would be spinning at a faster rate as it left the muzzle so it seems to me that it would be no different than shooting a barrel with a fast twist the complete length of the barrel. I wonder though how a conical would have worked in the gain twist. Starting out slow twist and picking up rotation speed, would it not be the same as shooting a conical out of a barrel with a fast twist the entire length? I'd be interested in knowing if anyone out there has one of these barrels with the gain twist and how it works for them (using rb).

Again, I'm not "knocking" the "in-lines" or the guns with fast twist or those who enjoy them. I was more curious about the two twists offered in such guns as the Lyman GP - or for that fact, one with a compromise between a fast and slow twist (such as a 1 in 48) - if they allow the owner the best of both worlds in regards to the results of using a conical (such as hunting) and rb (such as in a rb only match) once they get a load worked up for each type of projectile or is one going to always work better than the other - thus making it more desirable to have a separate barrel with the different twists?

As always, thanks for sharing your thoughts.

 

[Hawg]

I had an Investarms Hawken .50 caliber, 1:48 twist. I used a PRB and 90 grains of powder. I also used a Maxi Ball with 90 grains of powder. Both worked pretty good. Hunting accurate anyway. Lee R.E.A.L. worked well also. I tried sabots when they first came out and they all tumbled.

 

[Captchee]

actualy the original Minie has a thick skirt , todays minie is a thin skirt .
also the original minie had an exspander plug in the hollow base that served to exspand the base even more .
we dont see those today .

but if your asking about modern inlines , it depends on what gun . The Doc Whites inline shot big Heavy lead very well , past that ill leave the modern ifo to the modern shooters

 

[Hawg]

Early minies had an iron expander plug, then they went to wood. Then they figured out if the skirt was thin they didn't need an expander. I have dug quite a few original CW minies and most have skirts approximately the same size as Lyman repro minies.

 

[B.L.E.]

If a Minié bullet is nose heavy enough and has enough hollow in the rear, it will actually stabilize and stay nose first even out of a smoothbore. I have shot .177 air rifle pellets out of a smoothbore BB gun and no matter the range, they hit nose first every time.
A Foster slug is an example of a bullet that uses nose heaviness for stability in a smoothbore.

 

[Captchee]

i have found the opposite Hawg at least with the mines we dug at Chickamauga . All had thick skirts , much thicker then the Lyman Minie .
but then , when i worked at MOI we had exsamples from the US civil war that had both very thick and rather thing skirts ,all within the same persons cartradge case . so the case mybe made i guess that it all depends on when and where the round was cast.

One of the issues I believe was happening with my own rifle is that the skirt on the lyman was to thin and would lose its integrity . But a solid based design wouldn’t expand enough
When I settled on Bernard , which is much like a Gardner
in its skirt . Then I started getting accuracy
Lyman sells a mould that’s close to it for the 54 cal . BUT its skirt is still to thin . So what I did was turn the skirt plug down alittle so as to give a thicker skirt . When I did this it produced 439 grain from the the 425 grain Lyman mould . The original Bernards i recieved from Shapel were 435 grain . so the Lyman mould cam in real close with minor modification
Here is a photo showing the difference
On the left is a 54 cal old style Minie design 445 grain .
On the right is the Bernard which Kinda looks like a Gardner but not a round at the tip or a thick in the skirt
Notice the difference in length .
But when we flip the round over , you really see the difference in the skirts .
. grated we are talking 54 vs 58 here .

Greg Edingtons had a very nice write up with photos many years ago , showing the diffrences in the Lyman moulds vs the originial , early and late mines as well as the Gardner and Bernard rounds

but if we compair the above Lyman minie to un fired originals . like those on this page which show the base cavity , then eather the lyman is a later design as the skirt is much thinnner

http://mrkash.com/activities/civilwarmodernwar.html

 

[Captchee]

As to the expanders .
If often wondered about them and why the fell from favorable use .
On one had , they were and added step in manufacturing . Combined with that possibly they were deemed not necessary for the type of shooting that projectile was primarily being used for .
Where they somehow less effective then simply producing a thinner skirt ??
Maybe , but then I have to wonder if that was really the case , surly Minie would have just designed the round to have a thinner skirt to begin with
Lots to think about for sure

 

[Hawg]

I've got some like your thick design and some even thicker but the thinner ones are by far more common. I used to have hundreds of them but gave a lot of them away. Here's a few but you can't really tell the thickness of the skirts. I'll try to get some better pics. There's even a couple of cleaner bullets with the zinc scraper intact.

 

[Hawg]

I didn't feel like digging out the big box but here's some of the same ones in the other pic.





Here's an interesting one.




Cleaner scrapers