Difference Between Button/Cut Rifling?

[J E Custom]

From Krieger's website:

"Q: Is there any advantage to a single-point cut-rifled barrel Vs other manufacturing methods?
A:We feel there are several: ​

• Most stress-free way to rifle a barrel.
• Bore and groove dimensions very uniform throughout an entire "run".
• On average the barrel lasts longer than a button rifled barrel.

A: This is not conjecture on our part. This is information reported to us by military armorers and also by very long-time competition shooters who have used a considerable number of both button-rifled and cut-rifled barrels."

I recently ordered a Rock Creek single-point cut rifled barrel--in part based on the above information that, until this thread, I thought was fairly universally accepted. I've been lurking on this site for a few years now and before making my barrel choice thought that the bulk of what I'd heard regarding single point cut rifled barrels was that they tended to last longer (specifically the throat area) than button rifled barrels in general. Just curious where this 'new to me' info is coming from.

If you log on to the Lilja web site and look in FAQ you will hear just the oppsite about barres life
so who do you believe.

All I can go by is the cut rifle barrels that I have owned did not appear to last as long as the
buttoned barrels "BUT" I have never owned two rifles of the same caliber to do a barrel to barrel comparison and the only cut rifle barrels I personaly have/had were in 7/08.7STW and
338. the 7/08 went away (lost some of its accuracy)with less than 500 rounds down the tube.

The 7STW Had less than 400 (Hard) shots through it befor I had to retire it, And the 338 has
not had enough rounds through it to tell.

But the buttoned barrels have all done better, New 7/08 800 rounds and still shooting, the 7 RUM has exceeded the 7 STWs round count and is still shooting great. Many years ago I started
shooting NRA high power matches so I bought a 40X range master that had a buttoned Hart
stainless barrel against everyone's advice and after 50 years and over 25,000 rounds it will
still shoot sub 1/2 MOA groups with iron sights. I realize that the 308 is not hard on barrels
but 25,000 rounds is. and the real test is my 30/378. With a 122gr load of H50bmg behind a
200gr bullet barrel life should be short but so far with years of shooting no signs of accuracy
loss has appeared.

Most of the better military rifles have chrome lined barrels for wear and my understanding of
the buttoned process it aligns the grain structure improving the wear characteristics on the
bore surface.

Is one better than the other ? I could not make that call because of lack of extensive data.
I just know what I have experienced.

PS; I still use Both cut and buttoned barrels and it just depends on what the person having
the rifle built wants.

J E CUSTOM

 

[Moman]

I know Michael had a terrible time with a 300 RUM in a cut-rifled barrel. He no more than got a sweet load developed and then the pressures increased due to increased bore wear/bullet friction and he'd have to re-tune his powder charge. Turned into a process resembling a dog chasing its tail..

Couple questions for you guys. In Phorwaths post above, he mentions pressure increases due to bore wear. I never thought about this but seems to make sense. I assume that with the roughness of the bore/throat, and the increased friction on the bullet, the bullet is not sliding through the rifling as easily. Wish I could word that better but you know what I mean. I shot my 300 WM again today, this gun has a lot continuous throat erosion. The throat has eroded another .010 in the last 30 rounds, close to .060 since new. I noticed today that the primers are flattening. This is all with the same components and lot #'s that I have been using for a few years. I've never had flattened primers before. Do you think it is possibly why this is happening?

Also, I have a Broughton 5C barrel sitting here for it. Going to keep the caliber the same. Once this is rebarreled, can I expect it to shoot cold bore shots accurately? I would think the answer is yes but would like to hear what you guys have to say on it. Whether or not button barreling induces more stress, Broughton says their barrels are triple stressed relieved. Shouldn't this eliviate the first shot being off mark?

 

[jmden]

Lilja Precision Rifle Barrels - Articles: The Making of a Rifle Barrel

Maybe it's somewhere else on his site, but after a quick purusal of the barrel making articles, Dan doesn't seem to compare cut rifling to button rifling in a negative fashion at all here. If anything he honestly portrays the potential shortcomings of button rifling without saying anything negative about cut rifling. That may just be Dan's style--wouldn't surprise me. Just trying to gather some info.

 

[Michael Eichele]

Also, I have a Broughton 5C barrel sitting here for it. Going to keep the caliber the same. Once this is rebarreled, can I expect it to shoot cold bore shots accurately? I would think the answer is yes but would like to hear what you guys have to say on it. Whether or not button barreling induces more stress, Broughton says their barrels are triple stressed relieved. Shouldn't this eliviate the first shot being off mark?

I have seen the effects of the 'cold bore' shot on both my cut and button barrels. This is a problem you can find with nearly every barrel. My opinion is that it has more to do with a reaction of a cold peice of steel when heated very rapidly than from stress issues. Cut, buttoned, a cold bore is a cold bore.

To me, a cold bore shot doesnt always meen a 1st round. I dont see fliers on round number one in the summer or when my barrel is 70 degrees from sitting in my warm truck. I do see it when my barrel is very cold. Ussually well under the 32 degree mark. Some have been more sensitive than others but I have seen all of my barrels do this.

Learn where your 1st shot goes and at what temprature this starts to manifest. When hunting in fair weather, dont worry about it.

Couple questions for you guys. In Phorwaths post above, he mentions pressure increases due to bore wear. I never thought about this but seems to make sense. I assume that with the roughness of the bore/throat, and the increased friction on the bullet, the bullet is not sliding through the rifling as easily. Wish I could word that better but you know what I mean. I shot my 300 WM again today, this gun has a lot continuous throat erosion. The throat has eroded another .010 in the last 30 rounds, close to .060 since new. I noticed today that the primers are flattening. This is all with the same components and lot #'s that I have been using for a few years. I've never had flattened primers before. Do you think it is possibly why this is happening?

It is hard to say but does sound consistent with throat and bore wear. Both my RUM's did it. One was slower to show it than the other but with both, I had to readjust my loads more than once. One was every 20 rounds after the first 70 till I hit 200-250 rounds and every 50-100 rounds after that. I gave up on it after 500ish. The other was a much slower proccess and still shoots very well after 1100 rounds through it albiet it is at a reduced load. 3250 with the 178 is all I can get out of her without pressure signs.

 

[Buffalobob]

I wanted a custom twist and Krieger charged $20 more.
If you go to a button rifle barrel maker what do they charge?

edge

For a custom twist you would need to talk to the barrel maker. He may actually have a button but just not advertise it. If he does not have a button then he has to order one to be made. That process takes time. I do not know if he will charge you or not. It seems it will vary upon whether he believes it is a useful button and others will want it. I have experienced it both ways. I believe the cost of a button was about $300 five years ago.

As strange as it may seem, there is a lot of skill and craft that goes into a barrel. It may take the barrel maker several attempts to get a new button to produce a quality barrel. I do not understand it well. It is more than just putting a cylindrical piece of steel in a machine and pressing the "run" button

Given my experience I would recommend if you want a special twist that you go the cut barrel route and pay the twenty dollars. You will have your barrel a lot sooner (perhaps ???? speed is not something the gun building industry is famous for).

 

[edge]

Just a question, not an argument

Wouldn't throat erosion be in the throat? That is put in by the chamber reamer and not the barrel maker....
What am I missing?

edge.

 

[Michael Eichele]

Just a question, not an argument

Wouldn't throat erosion be in the throat? That is put in by the chamber reamer and not the barrel maker....
What am I missing?

edge.

Throat erosion happens from too much heat and flame with overbore cartridges. It can be minimized with quality steel and steel that is hardened to the right rockwell specs. As stated, sometimes throat life or lack of can be a bi-product of normal manufacturing proccess regardless of steel and hardness.

 

[jmden]

http://www.longrangehunting.com/forums/f19/i-need-help-barrel-understanding-4903/

 

[lazylabs]

Does anyone have any tested rockwell numbers for the inside of cut and button barrels? If you tested a button barrel before and after rifling would it show a marked difference? I am talking about taking a section of the chamber end, splitting it length wise and testing on the actual bore.

 

[TOM H]

Here is apretty good artical on makeing rifle barrels

The Making of a Rifled Barrel, FirearmsID.com

 

[Chas1]

Excellent reading on the making of a barrel. Thanks for posting.

 

[load]

Tight lipped? Or Clueless?
I queried many top button barrelmakers in the past about this, and none, not one, accounted for stress/bore changes as part of their process. .

uhhhh read on mcgowens websitethey account for it!


side note... the reason button rifle barrels hold up and last longer than cut barrels is simple. the act of pressing the button threw the barrel presses and hardens the surface of the bore.
done right they are both accurate. done wrong and neither will shoot

 

[Moman]

the act of pressing the button threw the barrel presses and hardens the surface of the bore.

Pulling the button would have the same effect.

 

[cutrifled]

Bounty Hunter,
All button barrel makers I know contour after the barrel is rifled , because you need the same diameter steel so you have the same amount of resistance down the bore as the button is being pulled to maintain consistent bore and groove diameters from breech to muzzle. I have produced both Button barrels and cut rifled barrels so I know both processes very well.

Load,
I want to know how you think the bore is going to maintain it's harness after you heat treat the barrel after buttoning to remove any stress induced into the steel during the process? Plus after you are done heat treating it for stress after buttoning it also gets heat treated after contouring to remove stress induced during the contouring stage. Then you will be removing any of the surface hardness from the steel during final lapping.


Paul Tolvstad
Rock Creek Barrels