rate(s) of twist chosen

[tom in nc]

I've wondered if there is or was ever a reason for the different rates of twist in rifled barrels. I know that faster rates are considered to be best for cast bullets and slower rates for patched round balls. I believe that all my rifles are either 1:48 or 1:66. I shoot patched round balls in all mine. But I wonder how someone originally picked the numbers? 1:48 makes sense with 48" being exactly 4' I suppose but 1:66? Just wondering.

 

[52Bore]

Most likely, trial & error as to what the maker preferred…
IMO- it was the British and their agreement with engineering genius Sir Joseph Whitworth in the 1850’s - 4 years of trials/experiments/testing (400yd inclosed range) to establish the 52bore (0.451”) 1:20 twist that set the tone for twist rate to bullet length, into a science.
later in the 19th Century: Greenhill’s formula was a mathematical equation to estimate optimal twist as well.

 

[Comfortably_Numb]

Most old ml's have one twist in the length of the barrel.

 

[SDSmlf]

Original Jaegers had one twist to match the barrel length. Plenty of 30” or shorter barrels.

 

[SDSmlf]

Didn’t see the Evil One’s post until after posted mine.

 

[nkbj]

Yo Tom.
Some good reading about the mid 19th Century US military experiments.
https://archive.org/download/cu31924030757474/cu31924030757474.pdf

 

[SDSmlf]

Maybe one of the Hawken experts can chime in, but I have seen it written that they would give customers whatever twist rate they desired, as long as it was 1-48”. Though there is a lot of information out there about the Hawken brothers and it hard to know what to believe.

 

[rich pierce]

Most simple rifling machines of the 1700s to early 1800s were not at all adjustable and quite a bit of work went into making the wooden screw more than 4’ long and perfectly laid out and running smoothly in the headstock. So, small time shops probably had one twist for all calibers. And it turns out that 1:48 can work from .45-.54 calibers pretty well.

Also even our predecessors probably figured out the relationships between ball size, velocity, and spin rates needed for accuracy.

 

[tom in nc]

There are videos on Youtube under the name Homemade History, by a guy from Germany showing how he built his own rifling bench. Although I'll never need a rifling bench, I guess, the videos are very interesting. He speaks English.

 

[LANEY REECE]

Yo Tom.
Some good reading about the mid 19th Century US military experiments.
https://archive.org/download/cu31924030757474/cu31924030757474.pdf

GOOD read Bud, THANKS

 

[Johnny Tremain]

1/60 thru 1/72 are Optimum for round ball.
If your buying a production barrel, you are going to get what the manufactured decided was best.
1/48 is an all around twist. They do it that way so you can use what you want. Cept you results may very.
I use a 1/60 rice barrel. Because its swamped, stress relieved, deep radius cut with .012 grooves.
Which is way better than any production barrel.
Most production barrel at button cut, which is the shallowest and cheapest way to make a barrel.

 

[45man]

Greenhill does not work on small arms of any kind, it was for cannons.

 

[Comfortably_Numb]

Maybe one of the Hawken experts can chime in, but I have seen it written that they would give customers whatever twist rate they desired, as long as it was 1-48”. Though there is a lot of information out there about the Hawken brothers and it hard to know what to believe.

I doubt the Hawken Bros made their own barrels. I'm sure they were made in barrel mills out east.

 

[SDSmlf]

I doubt the Hawken Bros made their own barrels. I'm sure they were made in barrel mills out east.

You could very well be correct about, but it still seems many were 1-48”.

 

[Comfortably_Numb]

You could very well be correct about, but it still seems many were 1-48”.

1 in 48 was pretty standard back in those days.

 

[52Bore]

Greenhill does not work on small arms of any kind, it was for cannons.

Thought I was going to learn something new..
Had to search to find out..
Probably can be used with Cannons.

 

[ETipp]

Maybe one of the Hawken experts can chime in, but I have seen it written that they would give customers whatever twist rate they desired, as long as it was 1-48”. Though there is a lot of information out there about the Hawken brothers and it hard to know what to believe.

Indeed. I find it interesting that for much of it, history only tells us what the authors told things as they saw it. Not necessarily how it actually was. We can get somewhat of the overall facts, but there’s still room for error.


Tom in nc, generally speaking, a slower twist will accommodate round balls best. 1:60 to 1:66 are common.

A 1:48” twist can shoot both conical and round ball okay, but is not always great at either.

A faster twist is best suited for conical.

There’s also depth of the rifling to consider.

 

[Sean E Bug]

it is all about stabilizing the ball. larger balls can have slower twist rates than smaller ones. small calibers like 25 and 32 are great at a faster pitch like 1:32 while something like a 4 bore can go as slow as 1:144. but 1:48 and 1:66 works good for most calibers between 40 and 60.

 

[Comfortably_Numb]

it is all about stabilizing the ball. larger balls can have slower twist rates than smaller ones. small calibers like 25 and 32 are great at a faster pitch like 1:32 while something like a 4 bore can go as slow as 1:144. but 1:48 and 1:66 works good for most calibers between 40 and 60.

Yes, that is all true for today, but it was much different back in the day.

 

[shorthair]

Military and builders did an amazing amount of research in several areas including both long range and rate of fire, both of which were of interest to sportsman and Military planers which made money available .