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Need CNC milling machine advice for odd barrel fluting

You can go with a much bigger diameter and increase the torsional stiffness. Fluting done correctly will reduce mass. ... infantry don't want to hear it but a heavy weapon is an accurate weapon.
This was my point. For every action there is an equal and opposite reaction. The point of a barrel is not to resist twisting, we don't wind up our guns like a rubber band, it's to direct the path of the projectile being accelerated down that guideway. The lighter the barrel is, the less mass. The less mass, the more it is pushed around by the explosion contained within. It seems to this novice that a 100 lb barrel with a 22 caliber bullet would be extremely accurate. That's not practical but reducing the mass of the barrel seems like it's going the wrong direction, for inertia/accuracy purposes.
 
This was my point. For every action there is an equal and opposite reaction. The point of a barrel is not to resist twisting, we don't wind up our guns like a rubber band, it's to direct the path of the projectile being accelerated down that guideway. The lighter the barrel is, the less mass. The less mass, the more it is pushed around by the explosion contained within. It seems to this novice that a 100 lb barrel with a 22 caliber bullet would be extremely accurate. That's not practical but reducing the mass of the barrel seems like it's going the wrong direction, for inertia/accuracy purposes.
Then the other dumb ass thing they do is put a big fatty of carbon fiber on them.1703863954440.png
 
Inconvenient rules limit weight. I'm not an expert here but there is an experimental class (guns are the experiment not the shooters in this case) unlimited weight on rails. Be careful you are about to waken the barrel harmonics crowd. Before you know it they'll be quoting nodes, jump and powder loads and then we will have a shit fight on our hands.
 
Thanks for the photos of the Hobber that is quite the machine.

I’m leaning towards CNC I already have a Acra 10x50 knee mill with manual a rotary on it. If I just wanted to do a straight flute profile on it.

I am sorry, I should have stated I knew centroid was a control.

I would love a haas but im wanting a more open work area mill to do the work. Im wanting to do. I may go to the Haas outlet and see a machine up close to see how they would be to work in. I had to bypass my safety’s on my tl to do chamber work.

I build a lot of my own tooling. The cnc Mill would greatly enhance some of my hare brained ideas to do this work.

God Bless,

Dustin
 

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Inconvenient rules limit weight. I'm not an expert here but there is an experimental class (guns are the experiment not the shooters in this case) unlimited weight on rails. Be careful you are about to waken the barrel harmonics crowd. Before you know it they'll be quoting nodes, jump and powder loads and then we will have a shit fight on our hands.
Harmonics and barrel whip, legit! watch what road we start down, it could get ugly!
 
Thanks for the photos of the Hobber that is quite the machine.

I’m leaning towards CNC I already have a Acra 10x50 knee mill with manual a rotary on it. If I just wanted to do a straight flute profile on it.

I am sorry, I should have stated I knew centroid was a control.

I would love a haas but im wanting a more open work area mill to do the work. Im wanting to do. I may go to the Haas outlet and see a machine up close to see how they would be to work in. I had to bypass my safety’s on my tl to do chamber work.

I build a lot of my own tooling. The cnc Mill would greatly enhance some of my hare brained ideas to do this work.

God Bless,

Dustin
Then the other dumb ass thing they do is put a big fatty of carbon fiber on them.View attachment 421059
People want it… That is the next project/Process I am pursuing.
God Bless,
Dustin
Harmonics and barrel whip, legit! watch what road we start down, it could get ugly!

Don’t forget the magical “Tunner” Muzzle Brake market I could pursue with a 4th axis.

God Bless,
Dustin
 
I would love a haas but im wanting a more open work area mill to do the work.
Dustin apologies for all the crap we posted on your thread. A machine that is excellent for the type of work you want to do is a Deckel 60T could be e wrong on the model number it's been a minute. It's a 3+2 mm machine, you can set up a barrel vertically dial it in perfectly with a rod and then chamber and thread in one hit. 12 tools from memory and super easy access. With a 4th it would be perfect and it has a Heidenhain control that is a joy to work with.
 
I would love a haas but im wanting a more open work area mill to do the work. Im wanting to do. I may go to the Haas outlet and see a machine up close to see how they would be to work in. I had to bypass my safety’s on my tl to do chamber work.
If you want an open, inexpensive CNC, I would personally look at the Milltronics, they still make a few toolroom CNC mills without full enclosures.
 
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The beauty of the Deckel is the low stationary table and the way the machine enclosure opens. The only issue I ever had on them was the tool changer by it I've found this on all Deckels
 
I think (?) the concept behind the thick barrel is it lowers the natural frequency at which the barrels resonates. That's a fancy way of saying the barrel will vibrate less when a bullet passes through it. Less vibration equals a higher degree of accuracy and repeatability.

This is similar to why a heavy vise on a heavy workbench will provide a better whacking surface than a flimsy vise mounted on an old car tire. With the car tire vise, every whack has half its energy wasted and you'd better plan to re-aim your next blow or it'll miss the mark.
 
Thanks for the photos of the Hobber that is quite the machine.

I’m leaning towards CNC I already have a Acra 10x50 knee mill with manual a rotary on it. If I just wanted to do a straight flute profile on it.

I am sorry, I should have stated I knew centroid was a control.

I would love a haas but im wanting a more open work area mill to do the work. Im wanting to do. I may go to the Haas outlet and see a machine up close to see how they would be to work in. I had to bypass my safety’s on my tl to do chamber work.

I build a lot of my own tooling. The cnc Mill would greatly enhance some of my hare brained ideas to do this work.

God Bless,

Dustin
Interesting indicator fixture for dialing in chamber reamers. Have you considered sag with that set up? Indicators are comparators good in the plane they were zeroed in. Your reamer is not where you think it is. Mount your gizmo to a block with a chamber reamer mounted solid to the block and flip the thing over. You freak out at the amount of sag.

As for a fluting mill, buy an old Fadal with a 4th axis. You'll invest about 10 grand with rigging, they go cheap at auctions. I would build a few spring loaded steadies for under the barrel to dampen vibrations.

Good luck.
 
Interesting indicator fixture for dialing in chamber reamers. Have you considered sag with that set up? Indicators are comparators good in the plane they were zeroed in. Your reamer is not where you think it is. Mount your gizmo to a block with a chamber reamer mounted solid to the block and flip the thing over. You freak out at the amount of sag.

As for a fluting mill, buy an old Fadal with a 4th axis. You'll invest about 10 grand with rigging, they go cheap at auctions. I would build a few spring loaded steadies for under the barrel to dampen vibrations.

Good luck.
My thoughts on sag is. We have to draw the line somewhere… The precision ground pilot, seems to line up in the bore perfectly. I don’t see any movement on the indicator when it goes in and out during the chambering when I am on the reamer with an indicator.
I get zero run out from the front and back of my chambers and they are not oversized.
It’s taken a lot of trial and error to get to this point.
I can say for a fact there are lots of smiths bragging about dialing in chambers to .0002 but if you stuck an indicator on the back of the chamber after the cut it would run out up to .003 out of round.
Thanks for the information
God Bless,
Dustin
 
My thoughts on sag is. We have to draw the line somewhere… The precision ground pilot, seems to line up in the bore perfectly. I don’t see any movement on the indicator when it goes in and out during the chambering when I am on the reamer with an indicator.
I get zero run out from the front and back of my chambers and they are not oversized.
It’s taken a lot of trial and error to get to this point.
I can say for a fact there are lots of smiths bragging about dialing in chambers to .0002 but if you stuck an indicator on the back of the chamber after the cut it would run out up to .003 out of round.
Thanks for the information
God Bless,
Dustin
I saw a guy saying a couple tenths also, and he was holding it in a Jacobs drill chuck :bawling: :nutter:
 
Years ago, I was in a factory that made very high end equipment for high RPM. They had a lot of the best measuring equipment money could buy...I remember them telling me they would show me their new device that would measure something like .0002MM (this was in France) and could do it over a span of more than 3M. They took me into the QA room....then through a door down a specially built hallway that served to isolate the room the device was housed in. In that room, there was no furniture, windows, or anything but than the device and several gizmos that measured the room temp and humidity and elevation to a high degree of accuracy, all of which was used by the device to produce its readings. The device also sat on a specially poured foundation. At the time, they had spent over $2M on the device which would probably be $5M or more now. The point being....that was no Jacobs chuck measuring operation!
 
I can say for a fact there are lots of smiths bragging about dialing in chambers to .0002 but if you stuck an indicator on the back of the chamber after the cut it would run out up to .003 out of round.
Thanks for the information
God Bless,
Dustin

For a fact eh?

Presumably you've taken barrels and inspected them after chambering by a gunsmith who claimed to dial in the bore to .0002" before chambering and found them to run out of round? Question, how does the chamber get out of round? If the axis of the lathe and tailstock weren't inline/parallel maybe you would get a larger chamber opening and the taper would be greater, Out of round I don't think so. Maybe you meant out of concentricity?

And as for the bragging, getting .0002 TIR is not hard, can be time consuming (in my humble experience anyway ). I'd expect any half way competent gunsmith to be better then .0005" TIR. and the floating reamer holder will take care of the rest.

----------------------------------

FYI I don't consider my self a Gunsmith but have chambered plenty of 22LR match barrels.

One I chambered with a Bentz reamer (10/22). Looked down the lathe spindle from the left hand tailstock end and saw the muzzle end of the 20" barrel was running out maybe .020" Naturally thought I'd screwed the pooch. Nope upon inspection the first taper of the chamber was right on the money, and concentric with the diameter that fit in the receiver. Evidently there was enough play in the floating reamer holder and flexibility of the reamer to make a good chamber. Larger calibers with stiffer reamers maybe a different story.
 
If I was going to offer barrel fluting, I would either do it 100% or wouldn't touch it at all. The market demands interesting flute patterns that require full rotary axis integration. Personally what immediately comes to mind is a cheap (maybe Haas TL2) mill with a long X, a full rotary axis (there are used Haas 4th's everywhere), and an adjustable support system that you use to brace the barrel while it's being machined. That can be a really simple system you just adjust until it bumps into the barrel. I would use a slot milling cutter so it isn't suffering from the 0-speed center of a ball mill and cut the side of the barrel. It would be a monthly bill of ~$1,000-1,300. Dead simple, fast, lets the lathe do lathe work and the mill do mill work. I wouldn't dink around with converted knee/bed mills, they cost just as much money and loaded with headaches.
 
I wouldn't dink around with converted knee/bed mills, they cost just as much money and loaded with headaches

What headaches? A cnc knee mill is simple and parts are not proprietary like the haas TM1 - which is just a cnc bed mill on linear rails.

A cnc knee mill is also much cheaper. You could likely buy 2 for the price of a TM1
 








 
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