What is the best rifleing

[jlteague]

I have been wondering for I long time as to what is the most accurate type of rifleing. Is cut more accurate than cold hammer forged , or is broached more accurate than buttoned. Which is the best and why?

 

[cjl2010]

 

[Iron Worker]

Cut rifling. Also Bartlein bbls web site say bbls last 15-20% longer.

 

[shortgrass]

Hammer forged is what the big firearms makers do and use because it it is lower cost, barrel per barrel, than any of the other methods. Rifle barrels aren't broached, some pistol/revolver barrels are. Bartlein might claim their barrels will last 15-20% longer. 15-20% longer than what? Real BR shooters, those who actually participate in sanctioned matches, shoot cut rifled barrels 99.9%. They wouldn't if they didn't feel cut was the only 2nd best. In the end, the quality of the barrel may be the heart of the rifle, but 'the nut behind the trigger' will be the final 'component' that can make the difference when it comes to accuracy. For 99% of the shooters, cut or button rifled is a moot point. "Quality made" is the important part.

 

[KyCarl]

If break in is any indicator. My B.Obermeyer 5R cut rifled .298-.308 is a flat out winner!
26" MTU taper no fluting Thunderbeast thread over break.

 

[sable tireur]

Rifle barrels aren't broached

I think you'll all enjoy the following article:

3 Methods of Barrel Rifling: Pros vs. Cons
by NRA Staff - Tuesday, November 21, 2017

There are five barrel-rifling methods in general use: cut, button, broach, hammer forging and ECM (electrolytic cationic machining). All have their benefits. Today, we'll cover the first three methods.

1. Cut Rifling
Cut rifling is the oldest method of rifling a gun barrel. The cut-rifling method removes metal from the surface of the bore to create the grooves using a single-bladed, hook-type cutter of groove width that is pulled through the cold barrel. It is sometimes called "hook rifling" after the fishhook-shaped cutter used. Cutter depth is adjustable, so that it removes only a small amount of metalona pass. Each groove must be cut individually with multiple passes of the cutter. The cutter is indexed to each groove in turn and positively rotated by the rifling machine using a sine bar.

Advantages of cut rifling:

The shape and number of grooves and groove depth can be easily changed as necessary.
Rifling twist rate may be easily changed as required.
Rifling twist is consistent from one end to the other.
Little or no additional stress is imposed on the barrel.
Cut-rifled barrels may be contoured after rifling.
Close tolerance can be held.

Disadvantages of cut rifling:

The process is slow and not well adapted to mass production.
Cut barrels normally cost more due to the slower manufacturing process.
Some metal alloys can not be cut.
A mistake or machine malfunction at the end of the process can prove wasteful.
Cut-rifled barrels must be lapped.

Many target shooters prefer cut-rifled barrels for their uniformity and close tolerance. The cut-rifling method is normally used on prototype or test barrels where only a small number will be made for experimental purposes.

2. Button Rifling
Button rifling is a modern method that creates the grooves in the cold surface of a rifle bore by displacing metal using a bullet-shaped, super-hard button of tungsten carbide. The rifling button has the reverse pattern of the groove profile ground into its surface. As the rifling button is pushed or pulled through the barrel, the groove pattern is ironed into the bore surface by displacement. There are several variations in button-rifling procedure. Some barrelmakers prefer to pull the button through the bore, while others prefer to push it through. In most cases, the button remains free to rotate during this process, dependent on the angle of the grooves in its surface to cause the desired degree of rifling twist. As variations in rifling twist may occur during this procedure, some barrelmakers affix the rifling button to a rod and positively rotate it with a sine bar.

Advantages of button rifling:

The procedure is fast and very economical, as only a single pass of the button is required to rifle a barrel.
Button rifling is well suited to mass-production methods with high output.
Button rifling leaves a smooth, bright finish inside the barrel that need not be lapped.
Button-rifled barrels are very accurate.
Bore and groove dimensions are very consistent.

Disadvantages of button rifling:
Button rifling creates stress in a barrel; high-quality button-rifled barrels must be stress-relieved after rifling.
Buttons are expensive and difficult to make.
Different groove configurations and different rifling twists require a new button.
The button-rifling system is not flexible.

Button-rifled barrels can be extremely accurate; more bench-rest records are held by shooters using guns with button-rifled barrels than by any other type. Button-rifled barrels are very common on modern centerfire and rimfire guns.

3. Broach Rifling
Broach rifling is a modern, production-oriented variant of cut rifling that addresses some shortcomings of the cut-rifling process. While cut rifling uses a single-bladed cutter, a broach is a metal bar with sets of progressive cutting blades in its outer surface corresponding to the number of grooves. The cutting blades are fixed in spiraled succession, each blade cutting to slightly greater depth than the one in front of it. As the broach is pushed or pulled through the cold barrel, all the grooves are cut on a single pass. In some cases, a series of ever-larger broaches is run through the barrel until the desired groove depth is reached.

Advantages of broach rifling:
Fast and well-suited to mass-production methods.
Little or no stress is imposed on the barrel.
Rifling twist is consistent from one end to the other.
Broach-rifled barrels may be contoured after rifling.
Adequate tolerances can be held.

Disadvantages of broach rifling:
Broaches are expensive and hard to make.
Different groove configurations and different rifling twists require a new broach.
Broach-rifled barrels must be lapped.
The broach-rifling system is not flexible.
Match-grade barrels are not compatible with this system.

Because broach rifling was well-suited to high-volume production, it was the rifling system of choice in making military rifles during the first half of the 20th century. In the second half o the 20th century, button rifling replaced broach rifling for the manufacture of rifle barrels, with few exceptions. Today, broach rifling is commonly used to rifle some handgun barrels.

 

[jlteague]

Sable thanks a lot that was very helpful and informative, just the info I was looking for.

 

[jlteague]

Sable thanks a lot that was very helpful and informative, just the info I was looking for.

 

[BigDon]

Stress relieving seems to be a consistent issue here. I've using super cold stress relieving with race car engine components with some success. (Using liquid nitrogen) Do any of you have experience with this technique on barrels or receivers?

 

[KyCarl]

We did alternate hot and cold stress relief at the machine shop but I've never seen it on barrels? It was all timed and recorded?

 

[Aoudad shooter1975]

Yep all have pluses and minuses...I have had good button, hammer forged, and cut rifled barrels

 

[sable tireur]

And like so many fashion styles, the types of rifling have had a circuitous life among shooters. For ages it seemed like there was nothing to use to win benchrest competitions but a Shilen button barrel. Then along came the Bartlein, Krieger, Obermeyer, K&S and all the other cut rifled barrels which is the phase we're running through currently.

Fortunately, there are so many good barrel makers right now that it's hard to pick a bad manufacturer unless you try to get really cheap...

 

[sable tireur]

Stress relieving seems to be a consistent issue here. I've using super cold stress relieving with race car engine components with some success. (Using liquid nitrogen) Do any of you have experience with this technique on barrels or receivers?

This has been an offering for the last 25 years or so for firearms. As with most new mouse traps, everyone jumped on the bandwagon either to send barrels and actions off to the processors or to design and build their own processing service. And like every other new mouse trap, when it shook out, about 1/2 the folks liked it while the other 1/2 disliked it.

Here is one of the first suppliers:

https://www.300below.com/firearms-cryo-barrel/

 

[nvschütze]

Had a gorgeous stainless Hart; button-rifled. Wickedly accurate...