Tennessee or Iron Pennsylvania?

[stombaug]

I'm seriously considering either a Tennessee or Iron Pennsylvania rifle from TVM (Muzzleloading, not Manufacturing). I've done some research, read a bunch of opinions and testimonials about TVM, and most are really good, so I am kinda close to making a final decision.

Here's the part where I ask for "forum opinion": If I were to go with a .54cal, 42" barrel, what rate of twist could be considered "optimal", assuming that rifling cut is the same for different twist offerings? Most of what I have been able to find points toward 1/56", but I have also found barrels available with 1/70" and/or custom rates.

For the sake of argument, let's assume that 1/56" is the fastest rate that you would ever go with in this caliber and barrel length for PRBs. That being said, are there any distinct advantages or disadvantages of a slower rate?

As always, I look forward to your opinions... so "have at it!"

 

[Vaino]

1/56 or 1/66 would be suitable for a .54. Depending on the bbl brand that TVM uses, one or the other might not be available....check w/ TVM......Fred

 

[jamesthomas]

I would go with the 1/66 or 1/70 twist, slow twists are more forgiving in their accuracy range than the faster twist especially when you get up in the heavier calipers like a .54.

 

[Dphar]

As the subject says - this may be a bucket of the same old worms, but here goes:

I'm seriously considering either a Tennessee or Iron Pennsylvania rifle from TVM (Muzzleloading, not Manufacturing). I've done some research, read a bunch of opinions and testimonials about TVM, and most are really good, so I am kinda close to making a final decision.

Here's the part where I ask for "forum opinion": If I were to go with a .54cal, 42" barrel, what rate of twist could be considered "optimal", assuming that rifling cut is the same for different twist offerings? Most of what I have been able to find points toward 1/56", but I have also found barrels available with 1/70" and/or custom rates.

For the sake of argument, let's assume that 1/56" is the fastest rate that you would ever go with in this caliber and barrel length for PRBs. That being said, are there any distinct advantages or disadvantages of a slower rate?

As always, I look forward to your opinions... so "have at it!"

48", 56", 66", 70" and 72" will all work fine. I would lean toward the faster end but I try to use GM barrels and these are all at the slower end, 70" in 54.

Dan

 

[BrownBear]

I would lean toward the faster end....

Same here. In my experience, the really slow twists don't like reduced powder charges at all, while a 1:48 or 1:56 really does well with light loads while digesting big loads with fine accuracy.

It makes for a much more versatile gun. I load my faster-twist 54's down to 30-35 grains of 3f for popping bunny heads, yet get superb accuracy at the high end of the charge scale for big game. I have two 54's with 1:70 twist and neither of them is worth a hoot with charges below about 60 grains.

Hard to beat.

When you consider all the possible uses for a rifle, it kinda makes sense that the venerable Hawken brothers built their rifles with 1:48 twists, doesn't it? No knock on them for accuracy, by any means.

The whole "compromise twist" hair ball got started when TC brought out barrels for use with conicals as well as round balls, that also happened to be in 1:48. The point lost on all the slow-twist pushers is that the compromise was not in the twist rate, but in the rifling depth. Shallower rifling was needed for the conicals. In fact, to get the best accuracy with round balls in that shallow rifling, you really need a tight patch/ball combo in most rifles I've shot.

 

[stombaug]

So far, this is pretty much what I expected to hear... that there seems to be more disadvantage to a slower twist than advantage. I will have to check with TVM to be sure, but I am now leaning toward the 1/56, based on these few responses. I'll give a few more hours for a few more parties to chime in to see what others have to say. Thanks to you guys for your input!

 

[William O.]

Sage advice so far. My .54 is a 1:48 and is wonderfully accurate shooting PRB. In fact, both of my .50's have a slower twist; 1:56 and 1:60.
If I were to have another .54 rifle made it would have a 1:48 twist.

 

[LaBonte]

The late Bill Large, barrelmaker extraordinaire and one real character, claimed that 1/56" was the optimum twist for a .54 Caliber - he believed this so much that out of six .54 barrels I ordered from Bill back in the late 1960's and 1970's, four were sent rifled 1/56" even when ordered as 1/48" like the originals I was copying. You had to know Bill to appreciate it and the fact is that 1/56" was a VERY good twist (overall just a bit more user friendly than the 1/48") for the .54 in my experience and I never regretted keeping those barrels

 

[glrerun]

What about a Colorain swamped barrel with a gain twist that starts with a 1-96 twist that gradually becomes a 1-48 twist.

FYI regarding what LaBonte said about the 1-56 twist, that is exactly what Colorain provides in their barrels. In .50, .54 & .58 they are all 1-56 twist.

 

[galamb]

Even the barrel builders can't all quite decide what twist is "best" - they all have their own Voodoo calculators.

There is a few mathematical forumlae that are supposed to "help".

The "Greenhill" formula (says) Twist = 150 X diameter of the bullet (squared) divided by the length of the bullet (obviously with a ball all measurements are the same).

For a .530 ball that would give you - 150 x ((.53 X .53)/.53)) = 79.5 (if you trust my math)

So Greenhill says 1:80'ish for a .53 roundball.

But Greenhill didn't initially take into account "velocity".

Once velocity is factored into Greenhill, the twist drops a bit. At "typical" muzzle loader velocities you would only require a 1:70 twist for a 54 or 50 cal (Green Mountains Twist rate).

So next the "modified" Greenhill formula was born to try and come up with a "rule of thumb/one size fits all" calculation.

The Modified formula says take the caliber and multiply it by 1.25 = 54 x 1.25 = 67.5 (1:66 is what Rice uses)

Then there is the Miller Twist Rules which determine the "stability" of a projectile fired at X speed with Y twist.

Miller states that for stability you need to achieve a (stability) of between 1.5 and 2.0 for "stable flight".

A 54 cal (.530) roundball will achieve a score of 1.75 if fired between 1400 and 1700 fps (typical with 60 to 100 grains of powder) from a 1:56 twist barrel (the twist used by Colerain).

So you can flip a three sided coin :grin:

Greenhill says shoot a Green Mountain barrel;

Modified Greenhill says shoot a Rice; and,

Miller says shoot a Colerain.

Or you could say to heck with all of them and get a custom 1:48 twist 54 cal like the Hawken Brothers used to rifle in their shop. And you could argue they knew a little bit about making 54 cal rifles whose owners very lives depended on their functionality...

 

[Zonie]

The thing about the Greenhill and the Miller twist rules is, they were both made to determine the twist needed for a bullet, not a roundball.

A elongated object like a bullet needs to spin fast enough to create gyroscopic stability. The longer the bullet is relative to its diameter, the faster it needs to spin to prevent keyholing.

Roundballs don't need to spin to prevent keyholing.
They only need to spin fast enough to overcome the deflection forces caused by the wind hitting deformation or irregularities on the surface of the sphere.

I know it's fun to play with the calculations but the answers may not have a great deal to do with what is really needed for a spinning roundball to shoot straight.

 

[galamb]

Like I said, VooDoo formula's :grin:

I trust that whatever barrel I buy from any of the contemporary barrel makers will continue to shoot better than I do and will most probably outlive me as well.

But I do get that some will always be looking for the scientific or mathematical "grail" that will tell them what is better/stronger/faster (or is that superman?).

I personally believe that if you are a good enough shot that minor differences in twist, rifling depth, barrel length, coned/not coned, square or round rifling will make a difference in the accuracy of YOUR shot you certainly wouldn't "need" to be asking "what is best" on a forum such as this, you would have gained all that knowledge from years of shooting with countless different barrel combinations or you would be discussing it with other "championship" shooters.

In a (relatively) off the shelf barrel, where the builder has decided "most" of the specs, Rice just might be at the top of the pile (without starting an argument).

Given that, 1:66 IS the twist for 45, 50 and 54 cal round ball barrels.

For those, including myself, who occasionally "use Voodoo" we are fortunate enough to have barrel builders such as Charlie Burton/FCI and Oregon (just to name a couple) that will build in the caliber, twist, rifling depth, rifling style etc that you can possibly come up with.

At the end of the day, regardless of what I barrel I shoot, including 50 cal's (over the years) with twists of 1:70, 1:66, 1:56, 1:48, and 1:32, with rifling depths between .008 and .016, some round bottom and some square rifled, my groups are consistently sub 2" at 50 yards which is "Bambi Accurate".

I guess all my rambling comes down to "there is no grail", but if you believe that one will give you advantage over the other and need some science to make you feel better about your choice, you can find "loads" to support your choice even if it disagrees with the "loads" that support a different choice.

 

[Twisted_1in66]

An iron mounted Tennessee rifle would be a fine choice but an Iron Pennsylvania rifle would really be unusual. Prior to and during the Rev War, a gunsmith could actually be arrested for making steel parts as all of those were supposed to be imported from England. Additionally brass was very commonly available; was easier to work than iron or steel; and was less expensive too. I wouldn't say there were no Iron Pennsylvania rifles but it would not only not be common, it would be very unusual.

So it you're concerned about period correctness, I'd go with the normal brass on the Pennsylvania Rifle. Not nearly so unusual for a Tennessee rifle because they were not made near any major British garrisons; trade was more limited; and the didn't much care if it was illegal or not. The Tennessee rifles were also made later than the PA rifles.

Now, just because it's not historically correct doesn't mean you shouldn't get it. If you just like the look of an Iron Pennsylvania rifle and don't care about period correctness, then get the iron version and enjoy it! It will, after all, be YOUR rifle. TVM will do your right no matter your choice.

Twisted_1in66 :thumbsup:

 

[Stumpkiller]

. . . a gunsmith could actually be arrested for making steel parts as all of those were supposed to be imported from England . . .

So all barrel blanks, lock parts and plates were imported? ;-)

The Colonies were also suppossed to pay six pence per gallon of molasses imported from the West Indies. Not.

 

[Twisted_1in66]

. . . a gunsmith could actually be arrested for making steel parts as all of those were supposed to be imported from England . . .

So all barrel blanks, lock parts and plates were imported? ;-)

The Colonies were also supposed to pay six pence per gallon of molasses imported from the West Indies. Not.

Hey Stumpkiller,

The longrifle barrels were made here because England didn't make them. But they did supply all the smoothbore barrels (fowlers and muskets). Prior to and at the beginning of the war, locks were imported from England by the barrel and the round-faced English locks were used in both rifles and muskets.

The Brits didn't much care about brass side-plates, pipes, and nose-caps but they didn't want the colonials making steel parts and you could be arrested for doing so. Britain would use the raw materials from America; manufacture the goods, and then sell the goods back to us. That was actually their business model. Britain primarily wanted the colonies to provide the raw materials but not do the manufacturing.

As you got away from the British presence, people used what they had because there was little chance of British enforcement of the laws and trade goods were harder to come by. That's why you more commonly see iron/steel fittings on southern rifles such as those from Tennessee and western Virginia and darn few on Pennsylvania rifles. The tidewater areas of Virginia (such as Williamsburg) also primarily used brass because the Brits were all over that area too.

Twisted_1in66 :thumbsup:

 

[stombaug]

You guys are awesome! :bow:

 

[rr11]

ClickFlash, Not wanting to get into the HC/PC thing you may want consider butt style. If you want a .54 I would not pick the Tennessee or the southern mountain rife there thin butt plates would not be very comfortable with heavy (hunting) loads. When I ordered my last rifle Matt talked me in to a different rifle due to the recoil in heavy calibers.

 

[kopfjaeger]

ClickFlash, Not wanting to get into the HC/PC thing you may want consider butt style. If you want a .54 I would not pick the Tennessee or the southern mountain rife there thin butt plates would not be very comfortable with heavy (hunting) loads. When I ordered my last rifle Matt talked me in to a different rifle due to the recoil in heavy calibers.

I agree with rr11. You should get a rifle with a wider butt plate since your getting a .54 cailber. A wider butt plate would be easier on your shoulders. Also you might want to consider a swamped barrel. The cost is more but a swamped barrel balances out the rifle nicely. Specially for off hand shooting. I have a TVM early virginia in a .50 caliber with a swamped barrel and it balances well and shoots excellent. :2

 

[Rickey Brown]

If I was wanting a .54 I would look seriously at the early Va. rifle. It has the wider butt plate and is a very comfortable rifle to shoot in larger calibers. My JP Beck style has the wider flatter butt and in .50 is very comfortable to shoot

 

[rr11]

The early Virginia rifle is what I went with (10 years ago) as my hunting rifle. I have a 36" half round barrel and it is a joy to carry. The deer hate it :wink: