1/48 twist & round ball?

[user 36911]

All you need to do is look at the precision barrels made by companies like Colerian and Green Mountain to just name two.

I talked to Green Mountain many years ago about twist. They told me they did a lot of testing for the ideal twist for round balls. They came up with 1-70 as the most accurate and if you bought a drop in barrel for your TC it was 1-70. I did that and bought a GM barrel for a Renegade. Accuracy increased by quite a bit. It was the most accurate PRB shooter i've ever owned and got me a lot of elk and muley's.

Have a look at what target shooters use. It won't be a 1-48 shallow groove barrel that is a compromise to shoot ok with a PRB and conicals. Any barrel that's made for a PRB won't shoot conicals for beans. Shoot conicals in a GPR and see how it does.

 

[Old Hawkeye]

WOW !!!Thanks so much for the wonderful knowledge packed reply's.. Almost makes me want to sell my Tikka stainless 6.5x55. Almost, but not really. Hope there is a 54 cal cap lock to come my way in the not too distant futhure.

There have been two 54 Renegades sell from the classifieds here in the last couple weeks. Just keep an eye out or run a "Wanted" ad here & you should be able to find one fairly soon. As others have mentioned, reboring or installing a barrel liner to change caliber or rifling is relatively inexpensive, as well. Good luck!

 

[user 36911]

There have been two 54 Renegades sell from the classifieds here in the last couple weeks. Just keep an eye out or run a "Wanted" ad here & you should be able to find one fairly soon. As others have mentioned, reboring or installing a barrel liner to change caliber or rifling is relatively inexpensive, as well. Good luck!

It's not that inexpensive. It will be $130 to have it done and then shipping to and from Bobby. Depending on where you live. That could be another $100 with todays shipping prices.

 

[LME]

I am looking for a 54 cal percussion ML . I will be shooting round ball ONLY !! I see rifles for sale that appeal to me but with a 1/48 twist. My ML rifles in the past have been 1/60 , or 1/66. Can any one assure me a 1/48 twist will give as good of accuracy with the RB as a 1/60 twist ?

A 1/48 twist rifling will shoot a round ball very well but it doesn't like strong loads. A slower twist will allow you to get more FPS !

 

[Rum River]

I have 32", 48" and 60" twist rifles in both .50 and .54 bore. All the rifles shoot round ball very well (one ragged hole) out to 50 yards. My experiences with the 48" twist mimics others here that the charges may have to be reduced a tad for optimum results.

Once I go out to 100 yards though my rifles with the 60" twist will significantly outperform the 32" and 48" twist rifles. Obviously a lot of factors play into this - ball diameter, patch thickness, propellant, phase of the moon, rotation of the earth, interest rates, property taxes, etc.

YMMV

 

[Hesp]

All you need to do is look at the precision barrels made by companies like Colerian and Green Mountain to just name two.

I talked to Green Mountain many years ago about twist. They told me they did a lot of testing for the ideal twist for round balls. They came up with 1-70 as the most accurate and if you bought a drop in barrel for your TC it was 1-70. I did that and bought a GM barrel for a Renegade. Accuracy increased by quite a bit. It was the most accurate PRB shooter i've ever owned and got me a lot of elk and muley's.

Have a look at what target shooters use. It won't be a 1-48 shallow groove barrel that is a compromise to shoot ok with a PRB and conicals. Any barrel that's made for a PRB won't shoot conicals for beans. Shoot conicals in a GPR and see how it does.
[/QUO Green Mountain sounds interesting. Are they still around ? Since I want a RB shooter only, 1/70 twist sounds like the way to go. Want to get it right the first time. Maybe find a Hawken style rifle with a ruined barrel & replace it with an after market 1/70 twist barrel. Would be the same as a new rifle .

 

[user 36911]

Hesp.......Green Mountain is still making barrels but they quit making the drop in barrels. You can still buy the bare barrel and fit it to your gun.

Or buy a different gun that comes with a deep rifling slow twist barrel. Like a Gemmer Hawken from Muzzle-Loaders.

 

[flashpoint]

Des52 mentioned that a lot of TC .45 rifles were made with a 1-48 twist but the grooves were shallow. Several gunsmiths did a visual inspection of my .45 Seneca barrel and said the bore looked good. However, I don't know or have the gadgets to determine if the grooves are shallow or deep? How could I find this out? Thanks. FP

 

[user 36911]

Pretty sure TC used shallow grooves on all the 1-48 twist barrels.

 

[Old Hawkeye]

Des52 mentioned that a lot of TC .45 rifles were made with a 1-48 twist but the grooves were shallow. Several gunsmiths did a visual inspection of my .45 Seneca barrel and said the bore looked good. However, I don't know or have the gadgets to determine if the grooves are shallow or deep? How could I find this out? Thanks. FP

You will need a set of calipers that measure to the nearest thousandth of an inch. They are $30 to $50 & are a very useful tool for any shooter for a variety of tasks. Measure from the outside barrel flat to the top of the land. Then measure from the outside of the barrel flat to the bottom of the groove. The difference in these measurements is the depth of your rifling. Don't make too big of a deal or obsess over the twist & depth thing. I have 3 rifles with 48 twist shallow rifling & they all shoot PRB & conicals just fine. I have two slow twist rifles that don't shoot PRB any better than the fast twist ones. There are two many nit-pickers on this forum that just confuse many newcomers to our hobby with their personal bias & opinion. It doesn't matter what the depth of your rifling is, because it is what it is & you already own it. There are 1000's if not millions of these guns out there so they must work for somebody. Just go get some ball & powder & go have some fun!! You'll figure it out along the way.

 

[Herb]

Hesp, I have built over 150 muzzleloaders from .36 to .58 caliber, with twists from 1 in 48 to 1 in 84, IIRC, and tested them all from the bench with a wide range of loads. I can tell no difference in accuracy that I could attribute to the rate of twist. Here is my second copy of Jim Bridger's Hawken with a 1 in 48 twist Oregon Barrel. The 120 grain powder charges of Olde Eynsford 1 1/2F were measured with a weight- corrected measure. (If you left-click the picture, it will enlarge).

 

[user 36911]

Herb......I'm guessing your 1-48 barrels are deep groove?

The 1-48 twist barrels I have a problem with are shallow groove like TC, CVA, Traditions etc.

 

[Hesp]

Seems like a deep grove is a for sure "want" with the round ball. Since the RB has considerably less contact with the lands & groves than a conical. it makes sense to me, to have deeper grove rifling.

 

[Herb]

MtnMan, I did not specify depth of groove when I ordered that barrel, although one can. It is what they cut standard for roundball. I think it is .010 to .012 deep. I relieved the muzzle lands down to the grooves for about 3/8 inch, then filed the grooves back in, like the Bridger and Kit Carson Hawken muzzles. My grooves now measure ,020 at the muzzle, but that is only at the muzzle and is not the true bore diameter.

 

[MSW]

it's been my experience (and you might or might not have the same result) that the rate of twist isn't that big a deal (within reason). There is a 'sweet spot' where the right amount of powder (and the fight granulation - 2F or 3F) will get you the tightest group ... the rate of twist seems to be more forgiving of variations in powder charge once the sweet spot is reached.
if you are really keen to have a slow twist and have the rifling a certain depth. I'm sure Mr Hoyt can accommodate you. I had him run a .54 (which was badly rusted) out to .62 smooth ... can't remember what it cost, but i do remember being quite impressed with his work.

also, check out Dutch Schoultz' method - this is the best non shooting accessory you can get for the money
http://www.blackpowderrifleaccuracy.com/

 

[user 36911]

MtnMan, I did not specify depth of groove when I ordered that barrel, although one can. It is what they cut standard for roundball. I think it is .010 to .012 deep. I relieved the muzzle lands down to the grooves for about 3/8 inch, then filed the grooves back in, like the Bridger and Kit Carson Hawken muzzles. My grooves now measure ,020 at the muzzle, but that is only at the muzzle and is not the true bore diameter.

Yeah, i'd call .010-.012 a deep groove. Pretty much like the original Hawken as you know. Deep groove with 1-48 twist.

I've said it before and i'll repeat it. I wish I could afford to have you build me a Hawken. Not many can build a Hawken as well or as accurate as you.

 

[gemmer]

IMHO, it's not so much that deep grooved, slow twist barrels can handle heavy charges. It's more of a case that depending on barrel length, they need a heavy charge to get enough spin on the ball before it leaves the barrel. That would apply to rifles with typical Hawken barrel lengths. That goes for minie ball rifles, too. I leaned that from Bobby Hoyt. I built a Richmond carbine from original parts including an 1861 barrel that was a mess inside. l had Bobby cut it to carbine length and reline it. He suggested a 1:48 twist instead of the original 1:72. When I asked him why, he said that skirmishers want the fast twist to keep the minie stable at 100 yards. He ws right. The Brits did the same thing with their two band and musketoon Enfields.

 

[William O.]

My .54 Investarms barreled cap lock has a 1:48 twist, as does my .32 Crockett rifle. Both are wonderfully accurate and I've shot many matches with my .54 using 75 grains of 2f. Accuracy is the same up to 85 grains and it definitely doesn't like 3f at all. 20 grains of 3f in my .32 is deadly. I have a .54 flint lock from TVM that has a 1-66 twist with round bottom rifling which I haven't shot yet but I'll start with 55 grains of 2f and go up from there. I only shoot round ball now but some years back I had a shallow rifling fast twist Great Plains Hunter barrel that had been shortened and fitted to a Cabelas stock. It took 95 grains of 3f to get the best accuracy out of a .50 conical but it would shoot one ragged hole into the bullseye at 75 yards.
The 1-48 twist rate can deliver excellent accuracy and was used frequently in historical terms. Depth of rifling has more to do with accuracy than twist rate in a lot of cases, you just have to work up a good load for your particular rifle.

 

[Danny Ross]

I guess learning something here today. Some here are trying to tell me something, that 90grs of 2F with a 54cal roundball is a light load . I guess it has to be, since it is being shot out a 1:48 twist TC Renegade. Now if I shoot that same load out of my 54cal 1:66 Roundball Twist barrel from the Thompson Center Custom Shop, I got years ago, it must Not Be a light load, because of the barrel's slower rare of twist. Now why didn't I know that. DANNY

 

[flashpoint]

You will need a set of calipers that measure to the nearest thousandth of an inch. They are $30 to $50 & are a very useful tool for any shooter for a variety of tasks. Measure from the outside barrel flat to the top of the land. Then measure from the outside of the barrel flat to the bottom of the groove. The difference in these measurements is the depth of your rifling. Don't make too big of a deal or obsess over the twist & depth thing. I have 3 rifles with 48 twist shallow rifling & they all shoot PRB & conicals just fine. I have two slow twist rifles that don't shoot PRB any better than the fast twist ones. There are two many nit-pickers on this forum that just confuse many newcomers to our hobby with their personal bias & opinion. It doesn't matter what the depth of your rifling is, because it is what it is & you already own it. There are 1000's if not millions of these guns out there so they must work for somebody. Just go get some ball & powder & go have some fun!! You'll figure it out along the way.

Thank you Hawkeye for taking the time to educate me as to how to check the rifling on my TC. It is much appreciated, and your advice hit home for me. And you are right, no matter the depth, I own the gun and I don't see another in the future. Good to hear that 1-48 twist shallow or not, shoots PRB and Conicals just fine. Thanks again