Making chambers from home made reamers?

[leftiye]

Hi, The title pretty well defines the subject I have in mind. On another thread "Reaming 357 mag Throat, and 357 Max throat" I laid out a possible way to change a 357 mag to a 357 max with a throater and a chucking reamer.

I also have several projects with other straight walled tapered cartridges where I am planning to either just use a factory plain chucking reamer or taper pin reamer and /or in conjunction with each other to make 25 Hornet chambers, 30 Carbine chambers, and .22 CCM variant (with .020" taper) chambers. I wanted to throw out this subject and see what you other guys with expertise in this area think.

For chamber necks or the body of a straight-357Max type case an oversize chucking reamer could be reduced in size with a tool post grinder and polished to produce a non-cutting body, and a non cutting pilot section (or even sleeved pilot) with a gap between, and the front edges of the full diameter flutes behind the gap sharpened to cut either a case mouth vertical shoulder, or any type of taper.

I am also interested in the idea of making taper pin reamers with a pilot by this method to use as forcing cone reamers for revolter barrels. I know the angle is somewhat slight as stock, but the appropriate section of the reamer could be made steeper and resharpened. How slight of an angle would work well, does anyone know? I guess this could also be done with a chucking reamer.

[KCSO]

You need to get Letard's book on machining. He has a whole section on cutting chamber reamers. I'll try and post the proper title when I dig out my copy. I know it is available from Home Shop Machinist and it was one of the best $20 I ever spent.

[Nueces]

All of Guy's current books are available from him at www.lautard.com. You can click to see complete tables of contents for his Machinist's Bedside Reader series.

Mark

[Frank46]

Somewhere in an old firearms book I seem to remember that back in the 30's or so taper pin reamers were used to make chambering reamers. Maybe this would provide a cheap source of reamers for you to experiment with. If you have a copy of machinery's handbook they would probably have in it a listing of the various dimensions for the taper pin reamers. Hope this may be of some help. Frank

[Pavogrande]

Have you considered making "D" reamers ? They work well for a few chambers, seems like there was an old rifleman article on their proper construction.

[leftiye]

Pavo, Never heard of them. Do you mean the half round kind of drill/ reamer?

Actually I am more asking here about how well some of our machinist types think the idea of making chambers this way will work out. I can make the reamers, just am not sure (never done this before)how accurate they might be or if there might be unseen problems.

[KCSO]

D's ot two flute reamers will work well for a few light jobs. I also have instruction for cutting chambers on a lathe, although I am a chicken, I rough on the lathe and finish with a good reamer.

[Pavogrande]

D reamers are relatively easy to make - turn on lathe, harden then grind to a "D" section -
they are only good for finish work -- What you propose is really a lot of slow work, grinding all that metal away -- All that grit on the ways -- Might be cheaper to buy a reamer -- Stock reamers to modify are not cheap either -- my 2cents

[ARKANSAS PACKRAT]

leftiye; The homegunsmith forum has a ton of information about making reamers, how to stuff with pictures. You have to look for it, but it's good stuff.
Nick

[uscra112]

There was an article in the Rifleman years ago about making "D" shaped reamers. Not all that hard to do, and they are said to work quite acceptably for a few chambers. But you DO have to have the ability to harden and draw the steel. And I'd want to see the video tape before I'd believe they would work well in some of these stainless steels.

One of the problems with altering commercial reamers is that they almost all have uniform tooth spacing. This can lead to "chatter" problems even if used in a lathe. See if you can get reamers with varying tooth spacing - there's a name for the type but I can't remember it now . . .

[uscra112]

Remembered where to find the Rifleman article. September 1950.

Those were the good old days, yes they were. No bloody packs of lawyers lurking behind every tree, you could buy anything mail-order, suburbians hadn't driven all the ranges away, if you went for big game in, say, Idaho, you wore real wool, and had to be able to ride a horse 2 or 3 days in and as many more to get out, or else not go, etc., etc.

[lar45]

I've made a couple of reamers from O-1 drill rod. I've tried getting 4 flutes with just an endmill, but 3 is much easier. The biggest problem I ran into was keeping the reamer from warping when quenching.

If you could find the right size reamer, I would still want a way to have a pilot on the nose to keep it centered.

When I made mine, I center drilled the end of the stock and tapped threads so I could make a pilot from brass to center. I used a hex head screw(8x32 I think?)(CRS happens).
I turned the shape I wanted, then polished to get as smooth as possible.
Use an endmill and cut just over center so you have an angled cutting edge when referenced from the center.
After the flutes were cut I heated, quenched in oil and touched up the cutting edges with a ceramic stone. They cut old Mauser barrell steel very easily.

I read someplace, maybe the homegunsmith forum, that to keep your reamer from warping, chuck it in a drill press, have it running while heating with a torch, then quench in oil while the drill press is still running.

I have a book on makeing rifle barrels. In it they say that just cutting 1 flute with an endmill will work fine for a couple of chambers. It also keeps the whole thing supported so chatter doesn't happen.

I've got some pics of one of my reamers floating around, I'll see if I can find it.

Here's one.

I had better luck makeing seperate body and neck reamers.
I picked up some 1 1/4" O-1 and cut slices off, then brazed on to 1/2" round stock to make cutters. I thought this one would work for cutting flutes, but being made of O-1 it didn't really want to cut O-1. It worked fine for cutting regular carbon steels though.

[leftiye]

Thanks Lar,
This was more what I was looking for. I've studied making these for years, my biggest headache is that the cutting of the back reliefs, especially on the shoulders and necks seems to need a set of centers on a superspacer (or indexing fixture), on a rotary table (or swivel base) on a mill with a toolpost grinder in the locked spindle. The flutes could be cut with the same indexing setup and something like a dovetail cutter.

You also probly would need to rough the whole thing in, then heat treat, and then grind a little to finish dimensions to avoid the warpage problem. So some kinda tricky precision grinding setup would need to be figgered out.

Pilots on such things as chucking reamers could be ground down with a toolpost grinder until small enough for a rotating sleeve to be put over. For the present, I'm only messing with chambers that can be made with chucking reamers and/or taper pin reamers, so no shoulders. I figger I'll use the chucking reamers to make the neck and chamber mouth in say a .25 Hornet, and then make the taper with a taper pin reamer.

[Goatlips]

My first time to the Gunsmithing board, I know better than to get anywhere near good steel with a Dremel.

Friend of mine found a huge box of gunsmithing tools and asked me what some of them were. I;ve been googling around for weeks and found myself right back here at Cast Boolits.

I think these are homemade chamber reamers. Almost all have square tapered ends as if they were made from 'brace & bit' bits. One is even wood, with a cutter insert.

Can you guys give me any information on them? I may have to post several times to get the pictures up. Thanks in advance!

Goatlips

[Goatlips]

Page 2
I think I get it now

Goatlips

[Bent Ramrod]

Goatlips,

That stuff looks old! Like museum-piece old. Nearest pictures I could find to some of your stuff was some woodcuts in Stelle and Harrison's "The Gunsmith's Manual." The following are just guesses, based on those pictures. Also, I'm having some trouble with the scale in your pictures.

The longer reamers look like maybe for shotgun chokes or forcing cones. You'd need to measure them to see if they relate to any standard sizes. The ones with the big flutes could be for barrel crowning or else are the biggest counterbores I've seen in a while. The thing with the flat part and the screw could be used with a piece of abrasive paper clamped with a piece of wood for lapping or polishing the interior of the barrels. Does the screw expand the tool diametrically or tighten a clamping surface laterally? The last picture is a milling cutter, from its thinness maybe for extractor channels.

I can't figure out what the thing with the little protrusion is. Is the protrusion an internal thread tool?

The general technology level of the look of the tools: the brace-and-bit shanks, the hand-finished look of the shanks on the milling cutter and the polisher(?) and the many tiny teeth on the milling cutter sort of argues that they're from the period of Stelle and Harrison's book, about 1883 or so. I guess if that's an Allen head screw on the polisher end the whole theory is out the window.

Just a sort of "best guess." Hope it helps.

[Willbird]

There was an article in the Rifleman years ago about making "D" shaped reamers. Not all that hard to do, and they are said to work quite acceptably for a few chambers. But you DO have to have the ability to harden and draw the steel. And I'd want to see the video tape before I'd believe they would work well in some of these stainless steels.

One of the problems with altering commercial reamers is that they almost all have uniform tooth spacing. This can lead to "chatter" problems even if used in a lathe. See if you can get reamers with varying tooth spacing - there's a name for the type but I can't remember it now . . .

Just a couple things .

416 stainless in my experience machines NICER than chrome moly steel .
D reamers were used by mold makers and many other skilled tradesmen to machine tool steels, my dad was one of them and taught me how to make and use them . From hands on experience work in a tool and cutter grind shop I know chucking reamers do NOT have evenly spaced flutes, we had to finger off each flute to index them to resharpen them. The older books on making tools referred to uneven spacing as "throwing them off" and often specified a certain number of holes on the dividing head plate as the proper amount to "throw off" to prevent chatter.

There was a method used to bore stem engine cylinders where the boring bar rubbed on the opposite side of the hole to make it more stable, the material that rubbed could be paper or wood or maybe leather in some cases....

Bill

[HotGuns]

The "D" reamers are by far the easiest to make.
You machine the profile you want then you mill half of the diameter off.
You heatreat the piece, then you stone it lightly on the cutting edge.

You really don't need any relief on it but its best to machine as much material as you can from the piece so that the reamer has less work to do.

Somewhere around here on this forum is one that I made to use for a bullet mold that I made for a specific weight spitzer bullet for my suppressed .300 Whisper.

I have since made several "D" reamers and they work surprisingly well. For cutting a single chamber or whatever may be, it is by far the cheapest alternative because they work and you can make them right there in the shop...if you use Drill Rod.

[sailor]

I have made three 25 hornet reamers: one is straight case, one is slight shoulder so I can resize and expand in one shot, and the third is a short case the same length as the Stevens 25 RF. I use these to rechamber old rifles that have a good bore (rare) that the original owners still want to shoot.
I use M-7 tool steel for all my odd reamers (about 20 wildcats for using new brass to shoot in old SS rifles). I shape the reamer on the lathe leaving .002" on all diameters. I next flute on the mill on a taper to maintain flute chip capacity. If you don't the flutes pack up, and will seize and break the reamer ( voice of experience). I use a plain end mill to make the flute, the depth I work out by 10X scale drawing. I next file the secondary relief (clearance) angle, leaving .020" at the soon to be cutting edge. I next heat treat in a vertical furnace made from a piece of 2" pipe, with a hole in the bottom for my torch. The torch is held at a tangent to the inside surface so I get a climbing spiral flame. The reamer is suspended in the center of the pipe, where you can see the color as it heats up. Also important is to be sure you have a reducing flame i.e. the flame is not blue but orange, meaning you have free carbon in the flame. You have to heat to orange but not to yellow (takes some practice) then quench vertically in light oil without stirring it around ( one side will cool faster and it will warp). Next you temper it in your lead pot for 20 to 30 minutes. Finally you stone that last cutting edge that is left (.020" by .001") by hand at 5 to 7 degrees, with some sort of wood guide that works for you.
To use it, you drill a bore sized hole in a piece of mild steel, and cut a trial chamber. Then I cast the dummy chamber with a mix of sulphur and chimney soot, push it out and check it. Chances are the reamer warped slightly, and the reamer is cutting oversize. This you fix by stoning off the high flute, and doing another trial chamber.
It sound like a lot of work, and it is. But they cut sooo much nicer than a "D" reamer. "D" or pod reamers have a tendency to pick up chips on the back side and gaul the chamber surface.
It takes me about 7 hours to make a complex reamer like a .25 x .375 MAX with a shoulder, but once you have it, with care you can use it many times without fear.
Too much information perhaps? I figured years ago, that if the old timers could do it so can I, and I do. I make mold cherries this way too.

[zuke]

I've had this site saved in my favorite's for year's, and post it once in awhile.

http://personal.geeksnet.com/soderst...berreamers.htm

Have fun!