chambering without reamer!

Seriously - price out what the CNC machine and tooling would cost to chamber a rifle barrel. Figure in the hours to program it for one cartridge and one action... now figure out how many cartridges and actions you may have to fit... program them in too. You are into a pretty tidy sum... for what purpose? Just because it can be done baring no expense? You could set up few gun shops with all the reamers, conventional lathes, milling machines, etc for far less money.

Seriously - a CNC machine is for production work... making hundreds of things all the same...
I can sell you a CNC lathe for under 100 grand US capable of chambering anything housed inside of a 3” OD by way or reaming or boring, or both.
Hours? If it take more than 5 minutes to program a chamber you’re on your coffee break.
The last shop I worked at had very little in the way of production. It was jobbing shop. I was writing, setting up, and running off 4-5 different jobs a day we used the manual Hardinge to polish a dowel pin from time to time.
 
My really nice $10,000 lathe and a hundred different reamers is way less than your $133,000. Like guntech said a whole gunsmith shop could be outfitted with many many tools for less than your one cnc lathe. In the right part of the woods the building to work in could be bought and included in the price for less than the cnc machine
 
My really nice $10,000 lathe and a hundred different reamers is way less than your $133,000. Like guntech said a whole gunsmith shop could be outfitted with many many tools for less than your one cnc lathe. In the right part of the woods the building to work in could be bought and included in the price for less than the cnc machine


Probably 6 or 7 gunsmithing shops could be set up really nice for $133,000.
 
Reamers are not expensive, they are cheap compared to CNC tooling ... I have reamers that have cut over 100 chambers and have never been reground... just the 'flats' lightly stoned with a flat India stone to remove buildup. CNC and CNC tooling are not cheap.


I rough out my chambers with drills and then under bore the body and then ream.

I agree with Guntech! You might be able to get some inexpensive CNC bits, but unless you a doing production it is very difficult to justify the machinery.

BTW, a CNC won't tell you it has hit an inclusion... a machinists hand on the tail stock will ;)
 
Only $133,000 ...

I can also sell you one for $500,000 US that will do two barrels at a time. Different chambers in each if you want. But it can also do everything else too.

Like I said, the last shop I worked at was far from a production shop. It had 6 CNC lathes, 3 CNC vertical mills, and 5 Cnc horizontal machining centres. You don't need to be running an automotive contract to have CNC machines and be.
If a basic machine shop with technology from 25 years ago were to go into gun smithing, they'd have much faster turn-arounds, their prices would be less and there would be no discernible difference in the quality of the end product.
Lol@inclusions. If your barrel blanks aren't free of inclusions, I don't want to shoot one.
Area419 comes to mind as a very popular gun smith that chambers on CNC machines. Cadex does as well. Short Action Customs is another. Kelbly's does. Robert Gradous does.
 
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Like I said, the last shop I worked at was far from a production shop. It had 6 CNC lathes, 3 CNC vertical mills, and 5 Cnc horizontal machining centres.
Area419 comes to mind as a very popular gun smith that chambers on CNC machines. Cadex does as well. Short Action Customs is another. Kelbly's does. Robert Gradous does.

The last shop you worked at was not a gunsmith shop relying on gunsmith produced income.

And I bet those gunsmiths mentioned use chambering reamers, just like we have been doing for ever.
 
I have cut a .45 colts chamber (4140 blank) using just a boring bar and a manual machine ( I'm just a hobby machinist & my equipment is equally "hobby" orientated) and it took me 6 or more hours to do the job. After I was finished that knowledge building exercise, I swallowed my stubbornness & purchased a "piloted reamer" ($250 can landed at my PO). The subsequent 15 chambering's using the reamer took about 1/2 hr each to center in the 4 jaw & cut.

the satisfying thing to me was that I can see no difference in the bored chamber or store-bought & reamed chamber...fired brass is identical....Bu as Guntech and the others all agree, at 6 hrs. or more on the manual machine would be completely inadequate from a gunsmith return standpoint.
 
The last shop you worked at was not a gunsmith shop relying on gunsmith produced income.

And I bet those gunsmiths mentioned use chambering reamers, just like we have been doing for ever.

I never said using a reamer was bad. In fact, multiple times I mentioned using them IN CNC machines.

I have cut a .45 colts chamber (4140 blank) using just a boring bar and a manual machine ( I'm just a hobby machinist & my equipment is equally "hobby" orientated) and it took me 6 or more hours to do the job. After I was finished that knowledge building exercise, I swallowed my stubbornness & purchased a "piloted reamer" ($250 can landed at my PO). The subsequent 15 chambering's using the reamer took about 1/2 hr each to center in the 4 jaw & cut.

the satisfying thing to me was that I can see no difference in the bored chamber or store-bought & reamed chamber...fired brass is identical....Bu as Guntech and the others all agree, at 6 hrs. or more on the manual machine would be completely inadequate from a gunsmith return standpoint.
I would never suggest to anyone to single point bore a chamber start to finish on a manual lathe.
 
I can also sell you one for $500,000 US that will do two barrels at a time. Different chambers in each if you want. But it can also do everything else too.

Like I said, the last shop I worked at was far from a production shop. It had 6 CNC lathes, 3 CNC vertical mills, and 5 Cnc horizontal machining centres. You don't need to be running an automotive contract to have CNC machines and be.
If a basic machine shop with technology from 25 years ago were to go into gun smithing, they'd have much faster turn-arounds, their prices would be less and there would be no discernible difference in the quality of the end product.
Lol@inclusions. If your barrel blanks aren't free of inclusions, I don't want to shoot one.
Area419 comes to mind as a very popular gun smith that chambers on CNC machines. Cadex does as well. Short Action Customs is another. Kelbly's does. Robert Gradous does.

I would hope that a blank is free from inclusions but not every piece of steel is absolutely perfect. More often I've run into problems when rechambering a used barrel.
 
Homemade D bit reamers are cheap and fairly easy to make and definitely cheaper than store bought reamers. Be sure to take your dimension off of a factory shell because the published dimension can easily be wrong.

cheers mooncoon
 
The original post was about boring a chamber using a cnc lathe.
Yes.
Just wrote this in 9 minutes, and with modern tooling and conservitive cutting contditions, it’ll take one minute and twelve seconds to cut. 6.5CM with .100” of freebore.

FFB9649F-3D53-4DE9-B9BB-29DEA7D136E1.jpg
 
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I think the vast majority will continue to buy a reamer compared to buying a CNC lathe.

Exactly. What's more, one can use CNC but the boring bar will still flex, the chips will still have to be cleared. I've seen a lot of precision boring attempted. Sometimes it worked well, sometimes it failed. Hydraulic valve bodies could be bored fairly well because the bore was larger and stubbier than a rifle chamber but, even so, it was easier, faster, and more consistently done with a form tool (reamer). A reamer can, to a certain extent, follow a slightly eccentric bore, a boring bar will not so, from an efficiency standpoint, a reamer is better too. Setup, while critical in both instances, is even more so if you want to bore the chamber. You can program your CNC to bore any shape you want to but it is the tool which has to do the cutting and a long, skinny boring bar just isn't the right tool for producing a precise and smooth hole and especially, a precise, concentric throat.
 
Exactly. What's more, one can use CNC but the boring bar will still flex, the chips will still have to be cleared. I've seen a lot of precision boring attempted. Sometimes it worked well, sometimes it failed. Hydraulic valve bodies could be bored fairly well because the bore was larger and stubbier than a rifle chamber but, even so, it was easier, faster, and more consistently done with a form tool (reamer). A reamer can, to a certain extent, follow a slightly eccentric bore, a boring bar will not so, from an efficiency standpoint, a reamer is better too. Setup, while critical in both instances, is even more so if you want to bore the chamber. You can program your CNC to bore any shape you want to but it is the tool which has to do the cutting and a long, skinny boring bar just isn't the right tool for producing a precise and smooth hole and especially, a precise, concentric throat.

That's a tooling problem, not a machine problem, and nothing says you have to cut the whole chamber with the same tool.
 
Peter ,
Unless the bore is dialed in perfectly at the throat and I mean perfectly it won't be 100% concentric using a boring bar a piloted reamer will follow the bore much better and cut a chamber that is more concentric imo.
I
 
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