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Making a chamber reamers

fourtynine

Aluminum
Joined
Nov 12, 2005
Location
southern u.s
If you had 1000.00 to by a machine to make chamber reamers what would you buy ? I already have mill, lathe, od grinder, surface grinder. So far I have turned the stock on the lathe, hardened, cut the fluts on the mill with a stone didn't like it. try surface grinder so so . Neither of these cut worth a crap, first one wouldn't even cut 12l14. ended up with a d reamer and a boring bar ,and it was a simple 45-70 reamer . I think sharpening is my problem or relief... Any advise appreciated, comments welcome.
 

[486]

Hot Rolled
Joined
Feb 16, 2014
Location
Minneapolis, MN
Mine seem to work fine, cut out of old car axle shafts, flutes milled (I always seem to mill the flutes backwards so it cuts left handed...) filed for clearance angle, hardened with an oil quench, then hand stoned for edge.
My D reamers would always do stupid stuff like warping or shattering.

Keep trying at it, you'll get it eventually.

Cut the flutes a few thousandths past the center to get some rake to the cutting edge. Use sharpie marker to make sure your reamer isn't rubbing where there should be clearance.
 

72bwhite

Titanium
Joined
Sep 26, 2012
Location
California, Ventura county
never make what you can buy
as far as machine well one of those fancy cnc tool grinder
after all it's just a reamer take a careful look at how at the grind on a ppg reamer
and copy it
 

GGaskill

Titanium
Joined
Feb 14, 2001
Location
Central AZ
You need a tool and cutter grinder to sharpen one; mill the flutes before hardening. Not sure you can find a good T&C for $1000. Maybe used. Unless you have more time than money, buying them is more efficient.
 

RWO

Cast Iron
Joined
Jan 8, 2006
Location
Texas
I doubt you can properly sharpen a chamber reamer on a standard tool and cutter grinder, but I could be wrong. I do know that it is possible to hand sharpen a chamber reamer with very high precision given the proper jig. Guy Lautard's, "Machinist's Third Bedside Reader" has complete coverage on how to build the jig and how to use it.

RWO
 

fourtynine

Aluminum
Joined
Nov 12, 2005
Location
southern u.s
did you cut the flutes above or below center? i cut these .010 below . on the mill i used a 90deg. stone with flood . 0n the surface grinder i used a 60 drg. cone stone. with mist. thanks for all replies good info advise. ill see what i can do with it.
 

[486]

Hot Rolled
Joined
Feb 16, 2014
Location
Minneapolis, MN
did you cut the flutes above or below center? i cut these .010 below
sounds good, I do .005"
As I ran through earlier ITT, I just mill the flutes soft, using a normal end mill in a cheap import 5C spin index. Then I file the clearance angle in to the trailing edge of the flutes, harden, then stone by hand.

Wildass guess, I'd bet you don't have enough clearance angle on them. Mark them all along the tops of the flutes with dykem or sharpie marker and see if they're rubbing where they shouldn't be. Once you've got them cutting, ink them again and see if one flute is doing all the cutting. If so, lightly stone that flute and try again. By the time the chamber's roughed in you'll have the thing tuned up real nice. (to languish in the drawer for the rest of its life, hah)

To the rest of the rabble, I'd rather spend a few hours making the reamer than the weeks it takes to get one shipped. My projects are usually strange junk anyways, like a TT33 in a 9x25 dillon based wildcat (couple mm deeper chamber because it fit in the mags). There's also the pride of "built not bought" and all that, too.

ETA: here's some from a x54R reamer I did
rough turned, no throat on this one
fp08ip.jpg

Look ma, left handed flutes. D'oh!
2q1z30y.jpg

Don't seem to have any after hardening, but I assure you, it was ugly and black, then with nice shiny cutting edges after stoning.
 

fourtynine

Aluminum
Joined
Nov 12, 2005
Location
southern u.s
Looks like mine anyway, I think your right it's relief I'll give them another try, most of my gunsmithing is one off , can't really buy a lot of reamers just to lay around , thanks to all,
 

Pete Deal

Stainless
Joined
Apr 10, 2007
Location
Morgantown, WV
I have a bunch of old books on gunsmithing. I swear I once read where guys used to make what I think they called "chamber floats". It was just a turned profile of a cartridge about like [486] shows above and then milled to half thickness and hardened. Not sure exactly what needed to be done for relief. One edge would be the cutting edge. The pilot I think stayed full diameter. This was more for a one-of chamber. I can't remember where I saw this though. This was back maybe 60-70 years ago when things were not quite so available.
 

RWO

Cast Iron
Joined
Jan 8, 2006
Location
Texas
I have a bunch of old books on gunsmithing. I swear I once read where guys used to make what I think they called "chamber floats". It was just a turned profile of a cartridge about like [486] shows above and then milled to half thickness and hardened. Not sure exactly what needed to be done for relief. One edge would be the cutting edge. The pilot I think stayed full diameter. This was more for a one-of chamber. I can't remember where I saw this though. This was back maybe 60-70 years ago when things were not quite so available.

This is called a "D-bit" reamer, and is an old technique machinists used to make a workable reamer when a regular fluted reamer was not available. It works, but cuts very slowly. The usual material is 01 drill rod. The final grinding to about 51% of dia. is done after hardening. American Rifleman magazine had an article on making such chamber reamers back in the late 60's.

RWO
 

fourtynine

Aluminum
Joined
Nov 12, 2005
Location
southern u.s
update

If you had 1000.00 to by a machine to make chamber reamers what would you buy ? I already have mill, lathe, od grinder, surface grinder. So far I have turned the stock on the lathe, hardened, cut the fluts on the mill with a stone didn't like it. try surface grinder so so . Neither of these cut worth a crap, first one wouldn't even cut 12l14. ended up with a d reamer and a boring bar ,and it was a simple 45-70 reamer . I think sharpening is my problem or relief... Any advise appreciated, comments welcome.

relief was the problem ,lots of info in 3rd bedside reader on this . i turn the base shape on lathe leaving .020 larger overall ,move to the mill cut the fluts with a 60 deg cutter then harden , go back to the lathe and grind to final size with a tool post grinder , i sharpen with the jig used in the 3rd reader ,
 

gwilson

Diamond
Joined
Oct 1, 2006
Location
williamsburg va
A half round reamer will cut smoother than most others of any kind. I use them and make them for cutting tuning peg holes for violins. One time I did make a 9MM reamer and it worked fine.

I think some of you guys need to be careful what you're attempting before ULTRA high pressure gas blinds you.
 

[486]

Hot Rolled
Joined
Feb 16, 2014
Location
Minneapolis, MN
I think some of you guys need to be careful what you're attempting before ULTRA high pressure gas blinds you.
What.

Well, better sell all my tools and take up sitting quietly in the corner. Knitting's just too dangerous what with those huge spikey needles.
 

john.k

Diamond
Joined
Dec 21, 2012
Location
Brisbane Qld Australia
When I was a kid,most gunsmiths made their own reamers from"silver steel".Shape turned in a South bend,flutes cut with a home made grinder,relief filed ,then hardened.Hand stoned after hardening.One of the tricks is to copper the reamer ,then its easy to see what is happening as you stone it.22Hornet,218Bee,and 222R were the main ones,and you needed good eyesight.I only make big straight sided cases, using Chinese reamers bought on the net for peanuts,easy to get size, taper and throat,even with my bad eyesight now.Regards John.
 

[486]

Hot Rolled
Joined
Feb 16, 2014
Location
Minneapolis, MN
Cast iron,if you do not think this can be dangerous,you HAD better go sit in the corner!! :)

All in life can be dangerous.

One who's making a chamber reamer is going to be well aware of the dangers inherent in firearms.

Like warning a riveter that the piston's not retained in his rivet hammer.
 








 
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