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LEARNING THE TWIST

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flashpoint

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I am not too much of a ballistics guy, but I shoot a PRB .45 Seneca with a 1/48 twist. I was wondering what other twists are out there (1/60 ?) for consideration if I wanted to drop in a new barrel? Also, in a .45, what kind of results could I expect from each of the other twists shooting a PRB? Thank you.
 

tenngun

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Many as stars in the sky.
1:28, 1:48.1;56.1:60,1:66,1:72,190 are all sen and many more continental guns had little different measurements before the metric system. When put in to inches it was uneven.
Bigger the bore often the slower the twist. Most Ml old rifles were I. The 1:48 range. Slower twist became popular in modern ml. Faster is often for conical but small bore RB guns often have fast twist. English rifles often had fast twist in .50 size guns but slow in some military guns it’s all real confusing
 

flashpoint

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Many as stars in the sky.
1:28, 1:48.1;56.1:60,1:66,1:72,190 are all sen and many more continental guns had little different measurements before the metric system. When put in to inches it was uneven.
Bigger the bore often the slower the twist. Most Ml old rifles were I. The 1:48 range. Slower twist became popular in modern ml. Faster is often for conical but small bore RB guns often have fast twist. English rifles often had fast twist in .50 size guns but slow in some military guns it’s all real confusing
Thanks Tenngun now I know a little more.
 

LawrenceA

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It is my understanding, I am sure someone more knowledgeable will opt in, that traditionally anything went with early guns having no rifling or straight rifling or one twist for the length of the barrel or gain twist even so it started slow and got quicker.
It seems it was the American Long Rifle that introduced the slow twist for PRB in the 1700's much to the amazement of the Continentals (coz it worked).

Generally today there are 3 groupings.
Slow twist for PRB which going from 32cal to 58cal is around 1:48 to 1:72.
mid twist for 45 and up is usually around (but not always) 1:48 and is supposed to be a compromise twist for PRB and conicals.
Fast twist of around 1:18 to 1:28 which is specifically aimed at shooting conicals.

None of this means you cannot use any type projectile in any gun or that it will or will not shoot straight enough.
Hope this helps
 

Grenadier1758

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In addition to the rate of twist, one needs to consider the depth of the groove. Those Jaeger rifles with the one full twist in the length os a barrel as short as 24 inches usually had deep grooves and shoot patched round ball very well. The 1 in 48" twist rate with grooves deeper than 0.008" shoot round ball. Slower twists generally require more powder for best accuracy.

Ultimately, getting your rifle to shoot a patched round ball to point of aim is all about load development which addresses twist rate along with groove depth, ball size, patch thickness, lubricant properties and powder charge.
 

Kansas Jake

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Another consideration is slower twist rifles often require heavier powder charges to achieve best accuracy. You may not want to shoot 110 grains all the time in your 54 for best accuracy. Obviously as in things with front stuffers this doesn't always hold true.
 

tenngun

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Targets from a Baker Rifle, bottom off hand vs short barreled smoothbore in a locked rest.
If you can’t read them in photo top is 300 yards nine foot target, about a 50-50 chance of hitting a man. Bottom targets seven feet 100 % of hitting a man sized target
 

flashpoint

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Great information. I appreciate all the responses. I have been shooting only 50 grains of 2F and being I wanted to increase my effective shooting distance from 50 yards accuracy to maybe 75 yards and to have greater put down energy, I was advised to switch to 3F and start at 60 grains. Per Kansas Jack and Grenadier that slower twists 1/48 sometimes require more powder for greater accuracy fits with what I want to achieve. Thanks everyone. Flashpoint!
 

LawrenceA

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Great information. I appreciate all the responses. I have been shooting only 50 grains of 2F and being I wanted to increase my effective shooting distance from 50 yards accuracy to maybe 75 yards and to have greater put down energy, I was advised to switch to 3F and start at 60 grains. Per Kansas Jack and Grenadier that slower twists 1/48 sometimes require more powder for greater accuracy fits with what I want to achieve. Thanks everyone. Flashpoint!
Flashpoint, I think you read Kansas Jake wrong. Slower twist can need more powder as will a heavier bullet, all else being even.
At the end of the day shot placement will be more important. Shoot what allows you to put the bullet where it is needed.
If you can't place the shot don't take it.
 

tenngun

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I’ve never tested this as all my guns have been 1/48 or slower and I don’t know how fast was typically found on English rifles :
8E5F040C-D0E8-483F-B6FF-F5EC8E8AD1C3.jpeg
38D04F6E-CAC5-4852-8B62-8DD84A5807DE.jpeg
 

LawrenceA

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I’ve never tested this as all my guns have been 1/48 or slower and I don’t know how fast was typically found on English rifles :
Interesting this text talks about the rear trigger being the hair trigger and the Hawken being a slow twist.
I had heard almost all current examples of real Hawken's were 1:48 so a middle twist.
But the bit about being easier to load for PRB accuracy makes sense with modern understanding.
If we accept that the required twist is a function of bullet length and that the longer the projectile then the faster the required twist, it makes sense that the accuracy of a PRB would be less affected by a change in velocity in a slow barrel than a fast barrel.

I really don't know about STEEL barrels being used at all during the 18th or early 19th centuries. Or about shallow grooves. I thought most PRB barrels have deeper grooves.

Later English bullet rifles such as the Whitworth, Henry etcetera ran 1:20 with a 485 grain bullet.
Early English probably went the one turn in the barrel so whatever the barrel length was.

Thanks interesting read.
 

tenngun

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Hanson wrote this in the 1960s. A .22 has about a 1/18, a 30/30 about 1/9. Was he thinking a 1/48 is a slow twist?
Was he looking at targets by people shooting repo’s with ‘ slow’ twist 1/66?
 

flashpoint

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It is my understanding, I am sure someone more knowledgeable will opt in, that traditionally anything went with early guns having no rifling or straight rifling or one twist for the length of the barrel or gain twist even so it started slow and got quicker.
It seems it was the American Long Rifle that introduced the slow twist for PRB in the 1700's much to the amazement of the Continentals (coz it worked).

Generally today there are 3 groupings.
Slow twist for PRB which going from 32cal to 58cal is around 1:48 to 1:72.
mid twist for 45 and up is usually around (but not always) 1:48 and is supposed to be a compromise twist for PRB and conicals.
Fast twist of around 1:18 to 1:28 which is specifically aimed at shooting conicals.

None of this means you cannot use any type projectile in any gun or that it will or will not shoot straight enough.
Hope this helps
It does help Lawrence, Thank you. Flashpoint!
 

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