RH or LH twist of rifling

[Char-Gar]

In the days of yore shortly after the first man climbed down from a tree and walked upright, police officers carried either a Colt or Smith and Wesson DA sixgun, most often in 38 Special. A decent quarrel could be started by advocating the the superiority of one make over the other.

To be honest, there were differences. Their cylinders rotated in opposite directions and so did the direction of rifling in the barrel. Though subtle, these could be felt when the handgun was fired. The direction of the recoil tended to be toward the direction of the rifling twist. This turned the handgun either back toward the line of sight or away from it. Some folks thought is was important but most did not. Of course if a fellow was left handed everything was backwards.

The British thought rifling in their service rifles should rotate opposite from what the Americans did. The Brits thought the rifle should recoil toward the head and body of a right handed shooter, to make for a fast second shot, rather than away from the body as American rifles did. When Remington and Winchester made the Pattern 14 303 rifles for the Brits, they twisted the rifling to conform to British thinking. After the British contract was filled and the design reworked into the US Model 1917, the rifling was changed to go the opposite direction according to American thinking.

Most folks today, don't give any consideration to which direction the rifling twist goes and don't realize it might have some effect on recoil. But, back in the day, folks thought it was important.

Just a little blast from the past......

[Hickory]

I think I read once that the direction of twist in a gun is directly related to the spinning of the earth.
In the northern hemisphere the earth spins a different direction then in the southern hemisphere.

If the twist is wrong for the hemisphere, it will destabilize the bullets spin quicker and it will yawl before it should.


Truth or fiction? I don't know.

[Ido356]

Until I read this post I never even thought about it, lol, but a boolit screwing its way through a bore is going to create some torque, how much?
I'm sure some one knows.
Does it make a real difference?
Don't know, but I guess it also the same reasoning why us "yanks", cars drive on the right side of the road, and the driver is on the left.
Just be thankful they did not reverse the bolt action too.

[montana_charlie]

The direction of the recoil tended to be toward the direction of the rifling twist. This turned the [firearm] either back toward the line of sight or away from it.
Is not the recoil of the firearm opposite to the twist direction?
Specifically, when the direction of twist is 'to the right', does not the [rifle] try to turn to the shooter's left when fired?
That is my experience with the Sharps 45/90 in a 'right twist' when shooting big, slow, 550 grain bullets.

CM

[geargnasher]

Until I read this post I never even thought about it, lol, but a boolit screwing its way through a bore is going to create some torque, how much?
I'm sure some one knows.
Does it make a real difference?
Don't know, but I guess it also the same reasoning why us "yanks", cars drive on the right side of the road, and the driver is on the left.
Just be thankful they did not reverse the bolt action too.

If you REALLY want to know, read F.W. Mann's The Bullet's Flight. Toward the end all that is discussed and formulae given.

Gear

[fastfire]

When I had the Berret 50 BMG using 750gr A-MAX I could feel and see the rifle rotate with recoil.

[wv109323]

Back when revolvers were commonplace in NRA bullseye a "Smolt" was common. The S&W action was used with a Colt barrel. The S&W action was easier to be "Smithed" with a good trigger but the Colt barrel had a twist rate more satisfactory for the 148 gn. WC bullet. The Colt barrel had the twist opposite of a S&W barrel and the Colt barrel was considered more accurate due to better quality in machining.
I don't think direction of twist is as important as good and proper quality.

[Mk42gunner]

The Gov't issue 1911A1 had left hand twist, I never really noticed a .45 torqueing in my hands.

I had a couple of 5½" SS Ruger Redhawks in ,44 Mag that would definitely torque to the right. The top edge of the trigger guard/ trigger mounting plate would scrape the top edge of my trigger finger in recoil; I could have used a left hand twist on those guns.

Rifles -- I haven't noticed any difference, but I haven't shot a lot of medium to large bore healthy recoil producers.

Robert

[Char-Gar]

I have shot allot of ammo through 1911 pistols and I mean ALLOT. Like Robert I have never noticed any twisting of the pistol in my hand. I had always supposed the rearward travel of the slide, trumped any twisting induced by the bullet traveling down the rifled tube. But, that is a supposition and not knowledge, much less science.

[CHeatermk3]

I think I read once that the direction of twist in a gun is directly related to the spinning of the earth.
In the northern hemisphere the earth spins a different direction then in the southern hemisphere.

Surely you jest!!
So why doesn't the earth unscrew and come apart at the equator?

[fouronesix]

Easy to figure out which twist direction is best. If when you flush the toilet, the water spirals down in a left hand twist, the best rifling twist would be right hand to counteract that force. Of course if the toilet gives a right hand twist then the best rifling twist would be left hand.

[KYCaster]

So why doesn't the earth unscrew and come apart at the equator?



Loktite!

You're welcome....
Jerry

[Digital Dan]

And here I thought it was the near perfect vacuum emanating from Washington.

[Scharfschuetze]

I believe that you gentlemen are referring to the "Coriolis Effect." Google it if you are interested in the formula for it and its application to ballistics.

It is indeed used in long range ballistics for artillery and is sometimes touched upon in Army sniper training.

My biggest argument against left hand twist rifling in my Lee Enfields is that it unscrews the jag from the cleaning rod! :)

[gandydancer]

Until I read this post I never even thought about it, lol, but a boolit screwing its way through a bore is going to create some torque, how much?
I'm sure some one knows.
Does it make a real difference?
Don't know, but I guess it also the same reasoning why us "yanks", cars drive on the right side of the road, and the driver is on the left.
Just be thankful they did not reverse the bolt action too.

US YANKS? careful there pilgrim them fighting words.

[Hickory]

Surely you jest!!
So why doesn't the earth unscrew and come apart at the equator?

I guess I explained that wrong.
But it was a long time ago since I read the article.

[BCB]

Surely you jest!!
So why doesn't the earth unscrew and come apart at the equator?

It's the "Commode-Flush" phenomenon...

I think if everyone in the southern hemisphere flushed at one time and no one in the northern hemisphere flushed, there might be a major problem...

Well, that's what I think!!!...

Good-luck...BCB

[Cowboy_Dan]

Easy to figure out which twist direction is best. If when you flush the toilet, the water spirals down in a left hand twist, the best rifling twist would be right hand to counteract that force. Of course if the toilet gives a right hand twist then the best rifling twist would be left hand.

You're joking, right? The water follows the path of least resistance. I have personally seen it spiral both ways here in the US and in Peru. The Coriolis Effect only affects projectiles in free flight. This is because when a gun relases a bullet, the spin of the earth continues but no longer affects said bullet.

[Char-Gar]

Dan...yes he was joking. It does not take long for a thread to deteriorate to either silliness or an argument on this board.

[AZ-JIM]

[QUOTE=Scharfschuetze;2960462
My biggest argument against left hand twist rifling in my Lee Enfields is that it unscrews the jag from the cleaning rod! :)[/QUOTE]

You have to start from the other end of the rifle to not unscrew it lol!

az-jim

[Scharfschuetze]

You have to start from the other end of the rifle to not unscrew it lol!

az-jim

Ha, ha! I even use a Parker Hale cleaning rod made in England and it still unscrews. :)

On the serious side though, and this is different from the Coriolis Effect that Hickory alluded to, is the spin or gyroscopic drift imparted from the rifling. While it is virtually unnoticeable at the ranges we mostly shoot at, it does come into play at extended ranges. At extended ranges, the projectile will deflect in the direction of the rifling twist. The US Military's 1903 Springfield and its 30/06 cartridge had a tremendous amount of long range research recorded on its performance. At 1,000 yards, the deflection imparted by its 1 in 10 right hand twist rifling displaced a projectile 13" to the right. This is slightly over 1 MOA at that range. As a bullet's rotational speed decays much more slowly than its velocity, the deflection goes up exponentially at greater ranges. At 500 yards, Army ordnance found that the same rifle and load will only deflect about 1 1/2" or about 1/3 MOA. If you look closely at a 1903 rifle's rear sight, you can easily see that it is slightly inclined to the left to compensate for this deflection caused by the right hand twist of the rifling.

[fouronesix]

You're joking, right? The water follows the path of least resistance. I have personally seen it spiral both ways here in the US and in Peru. The Coriolis Effect only affects projectiles in free flight. This is because when a gun relases a bullet, the spin of the earth continues but no longer affects said bullet.

:mrgreen: And here, I thought that was common knowledge! :kidding:

Yes, I believe the OP was alluding to the Coriolis effect. Where an object nearer the equator is traveling faster than an object to the north or south. It does affect long range artillery that has a long travel time to target over great distances. The effect is greater the closer the line of travel is to north-south (perpendicular to the equator) and the effect is lesser the closer the line of travel is to east-west (parallel to the equator). The effect for our purposes is so small as to be meaningless for small arms. This is often confused with spin drift that does have a measurable effect on long range small arms fire. The Buffington sight on an '84 Trapdoor is a good example of an offset already built into the sight for correction of spin drift…. but has nothing to do with the Coriolis effect.

Oh and to a previous post on this thread about right hand twist imparting right hand torque to a rifle when fired??? I think a right hand twist would impart left hand torque to a firearm when fired. Please correct me if wrong.

And dang it! I wanted right hand twist on the last barrel I put in a receiver but I blew in and used the wrong end to chamber so now it's left hand twist :(

[Ido356]

US YANKS? careful there pilgrim them fighting words.

Yanks not Yankies, as in the American Revolution.
BTW, "Pilgrim's" came from England, aka Brits and them might be fighting words, lol.

Isn't felt recoil, felt after the boolit exits the barrel?
Torque might not be felt at all, when I use my cordless drill and drill a small hole, I feel very little torque if any at all, but when I use my 1/2" 1hp drill and drill a 1/2" hole in steel, you sure feel the torque.
Not an educated guess, but I doubt the twist direction has any practical affect by the Coriolis Effect.