Rifling. Old subject but not really

[yotehater]

As far as the theory that using air pressure would be dangerous, never fire a firearm again. Including air rifles. They all rely on rapidly expanding air pressure to push the projectile down the barrel.

Rich

Rich rich rich, You are so funny.

Please, always remember to take your firearms and motor vehicles to someone else for service and maintenance.

 

[Dusty Stevens]

Well here is a a couple pics of a button barrel that one has been lapped the other has not you guess which one hasn't.View attachment 1040918

Wheres those reamer marks so i can tell which is which?

 

[BoydAllen]

Lilja website has a good picture of how he buttons a barrel . Looks like a solid steel billet with the twist thread cut into the outside . . Looks like there would be no way for the twist rate to change . http://riflebarrels.com/twist-machine/

Actually the rod that the button is attached to has to be longer than the longest barrel that will be rifled, and that leaves room for it to become a torsion bar, and the degree of wind up depending on the uniformity of the resistance it encounters, which can be caused by metallurgy, finish, or variations in lubrication. There are button processes where the button is pushed and those where it it pulled, some in which it is "driven" and those in which the angle of the cuts on the button create the twist and it is allowed to free wheel . Back in the day there used to be a service that you could sent a barrel to to have its rate of twist charted continuously down the bore. Because a cutter only removes what a half a tenth of material per cycle (working from memory here probably not quite right) in any case a very small amount, the twist is very even throughout. Years ago, Stu Harvey had one of the Oakley twist uniformity measuring machines like the one in the picture on Lilja's page, and he told me that after he started using Krieger barrels he had no more need of it because the needle would just vibrate. There was no variation in twist. He said that he would sell if for I think $700 if anyone was interested. That was many years ago.

 

[Someoldguy]

Well I am still waiting.

Wheres those reamer marks so i can tell which is which?

I've seen a few factory barrels that the manufacturer claims are button rifled. Every one had markings in the grooves and on the lands.
I've no idea who made the barrels Stan Taylor posted, but those look nothing like what I'm used to seeing for button rifled barrels that have not been lapped. One looks like it might be copper fouled a bit, but that may well just be lighting.
I've no idea what you guys are getting at here.
So far as I know, no one makes a button rifled barrel that requires no lapping. If you know something I do not, I'd appreciate it if you'd point me in the correct direction to enlighten myself.

I do not think this forum needs a fguffey of barrel bores.

What say you guys?

Sorry if this seems snarky. It's late and I just want to know what the heck you're talking about.

 

[Dusty Stevens]

I've seen a few factory barrels that the manufacturer claims are button rifled. Every one had markings in the grooves and on the lands.
I've no idea who made the barrels Stan Taylor posted, but those look nothing like what I'm used to seeing for button rifled barrels that have not been lapped. One looks like it might be copper fouled a bit, but that may well just be lighting.
I've no idea what you guys are getting at here.
So far as I know, no one makes a button rifled barrel that requires no lapping. If you know something I do not, I'd appreciate it if you'd point me in the correct direction to enlighten myself.

I do not think this forum needs a fguffey of barrel bores.

What say you guys?

Sorry if this seems snarky. It's late and I just want to know what the heck you're talking about.

Those are sectioned button rifled barrels made by douglas. They were sectioned from a piece before lapping and a piece that had been finish lapped. They were posted to show that a good button barrel does not have tool marks that require lapping out. If you see reamer rings or whatever in the grooves or lands that barrel wasnt built with care or attention to detail. Some think the lapping takes those marks out but it doesnt. They werent posted to ruffle any feathers or step on toes its just for knowledge. Some folks never get to see stuff like that.

 

[Dusty Stevens]

Sorry if this seems snarky. It's late and I just want to know what the heck you're talking about.

Sorry if i was snarky too. Im just another old grumpy bassturd.

 

[Someoldguy]

Sorry if i was snarky too. Im just another old grumpy bassturd.

No, not snarky at all. Thank you for telling me.

Another likely un-informed question.

I'd like to talk to Stan. Where might I reach him?

 

[IdahoSharpshooter]

yotehater,

You and Eddie are so funny...

Is there a different answer than the controlled burn rate of smokeless powder in a cartridge creates rapidly expanding gasses; and that expansion is what causes the projectile to leave the case, and proceed down the barrel?

 

[IdahoSharpshooter]

Butch,

as far as the Jaguar; since the engine is in the front, and the drive system is in the back, I would guess it is a push drive. That, unlike the current front wheel drive so in vogue which pulls the car.

 

[Dusty Stevens]

yotehater,

You and Eddie are so funny...

Is there a different answer than the controlled burn rate of smokeless powder in a cartridge creates rapidly expanding gasses; and that expansion is what causes the projectile to leave the case, and proceed down the barrel?

Lets just say thats 50,000psi of pressure instantly. It would be tough to get 50,000psi of air to push a button short of a controlled explosion and that probably wouldnt re-form the metal around the button rather it would kill everybody in sight like a pipe bomb. Theres plenty of videos on youtube about how a button is pushed or pulled thru a barrel. It takes a bunch of pressure to move a button thru a hole when its bigger than the hole to start with.

 

[Someoldguy]

Compressed gasses are no way to move an object under strain.

Drain the fluid out of a wood splitter and hook an air compressor to the valve.

Better be a high- pressure compressor.
And you'd best not be in the way when that log splits.

Air pressure on a rifling button . . .

 

[IdahoSharpshooter]

Didn't say "instantly". I need one of you experts to tell me how much pressure is required. I slug barrels to check diameter. If I can push a pure lead slug up and out the muzzle of a rifle, it can't take much.

Dusty,
isn't that what happens every you fire a round? Path of least resistance...

 

[dolek]

Damn,reading threads like this is like driving in Amish country...you can be going along just fine enjoying the ride and all of a sudden there is a big pile of crap in the road...do ya straddle it or run right over it .Being miserable all the time must suck bad ?

 

[Dusty Stevens]

Didn't say "instantly". I need one of you experts to tell me how much pressure is required. I slug barrels to check diameter. If I can push a pure lead slug up and out the muzzle of a rifle, it can't take much.

Dusty,
isn't that what happens every you fire a round? Path of least resistance...

Your lead slug is not displacing metal. This is like trying to fit that jag-wire thru a rabbit hole. Either the hole is gonna be the shape of the car or the car is gonna be the shape of the hole but either way like a barrel button it dont fit.

 

[JRS]

Butch,

as far as the Jaguar; since the engine is in the front, and the drive system is in the back, I would guess it is a push drive. That, unlike the current front wheel drive so in vogue which pulls the car.

Rear engine, Rich. It pushes, and, pulls

 

[Dusty Stevens]

View attachment 1040975
Rear engine, Rich. It pushes, and, pulls

I need that car

 

[JRS]

I need that car

 

[Stan Taylor]

View attachment 1040976

Sweet

 

[msinc]

On a button barrel, if it had tool marks- chatter, reamer marks, stripes, whatever wouldnt there be a corresponding mark on the groove just like the land? I mean that same metal is there its just displaced. We need a button barrel maker to chime in if only we had one

Yes sir it is. I really wish I had the camera attachment for my Hawkeye. I priced one once and it was ridiculous to say the least. I would like nothing better than to be able to post some real good borescope photos of barrels.
What I see, for the most part is that many factory and a few custom button barrels show quite a bit of tooling marks in the bore and yes it is just the same on the lands as it is the grooves. I could show you pictures of Remington, Winchester {pre and post} Shilen Match, Douglas, Shaw and Savage {current} and you would not be able to tell any difference because all of these barrels show just about identical type tool marks. As posted previously, most of the marks are just a surface "ghost" but they are there. The button smooths or irons them almost all the way out, but you can sure see it with the scope.
Now, Shilen select, Pac-Nor, Hart, Lilja, X-Caliber and a few others I have looked at show no tool marks. Older Savage barrels didn't either, and were the best factory barrels I have ever seen, at least appearance wise.
What's interesting is that many of the barrels listed above with a lot of tooling marks do not copper foul and yet some perfectly smooth custom barrels with zero imperfections that I have owned would foul terrible.

 

[dkhunt14]

And for makers who pull the button, I'm guessing they suck it through with vacuum.

If she was a female, you should marry her. Hate to see the size of that vacuum. Matt