Barrel Channel Cutter

[davec2]

A long while back I needed to inlet a few 13/16 straight barrels and got really tired of inletting by hand.  (This was long before there were people who did this for you perfectly on a pantograph machine.)  I made a hand plane that would cut the required shape, but it was still slow.  Then I made a special router bit that worked OK, but the fit was not all that consistent.  But in the corner of my shop, I have a 50 or 60 year old cast iron shaper that I never really used very much.  However, I made the cutter below for it and it will cut a beautiful barrel channel that fits like a glove full depth in one pass in maple.  The second picture is a piece of maple scrap with a channel cut.





I am building a pair of 3/4 scale rifles now - .32 cal old Douglas barrels that I have milled down to .690 across the flats.  The final photo is of a barrel channel cutter I had made to cut the .690 channels on the old shaper shown next to my original shaper cutter.  Although these are obviously only good for straight barrels, I have also used them to hog away 90% of the wood for a hand inlet.

[Darrin McDonal]

I have been thinking about this process for inletting. But my question is how do you make the cutters and what tools do you need to make the parts?
Thanks
Darrin

[T*O*F]

This is what is used by the Tennessee Valley school of gunbuilding.  They are ground from 1" square HSS shaper cutters.  These are almost impossible to find anymore, as everything being offered is carbide which is a bear to grind.  I have a complete set in 1/16" increments between 3/4" and 1"  To do larger channels, two passes are required.  Each has its own stop bushing for depth of cut.  You start the cut until you hit the stop bushing and the blank rides on the peg in the background.

Jackie Brown has a set that he told me he has been using ever since he started building guns and has never sharpened them once.  No comment!!   

You can also buy molding heads with interchangeable cutters like Dave's and grind the cutters from tool steel.  I opted against that way because if one of the cutters gets loose, it goes right into your gut.

Very often, if you have a furniture or cabinet shop near you, they grind their own profiles and will often do yours for a fee.

[Dphariss]

I have been thinking about this process for inletting. But my question is how do you make the cutters and what tools do you need to make the parts?
Thanks
Darrin

I made a much simpler cutter by slotting a rod and making a bit that fits the slot from O-1 attaching it with screws then using a lathe to cut it to shape then hardened it. When I get home, Sunday I will post a picture if I am able to remember after 10 hours or so of airplanes and airports...
I use it in my vertical mill.
A friend used to use the shaper and reground cutters for barrel channels and forends.

Dan

[fm tim]

If you get a chance, the Herchel House longrifle video shows him using a shaper to cut the channel in 2 passes.

[msblacksmith]

good job i wish i had a cutter like you made.

[whitebear]

I HAVE NOT TRIED THIS. However I recently read of taking old paddle bits and shaping them to the desired profile and cutting off he shank to a suitable length and using them in a router.  Anyone have any experience with this?

[bluenoser]

I haven't tried this either, but would not be inclined to do it.  A typical router hums along at about 25,000 RPM.  A cutter made from a spade bit could easily jamb or take too big a bite and, as I recal, the shanks can be quite soft.

Take it from one who knows.  You haven't lived until you've had a good sized router bit break loose and zip around the shop at 25,000 RPM!!!!!

Laurie

[Jesse168]

This is what is used by the Tennessee Valley school of gunbuilding.  They are ground from 1" square HSS shaper cutters.  These are almost impossible to find anymore, as everything being offered is carbide which is a bear to grind.  I have a complete set in 1/16" increments between 3/4" and 1"  To do larger channels, two passes are required.  Each has its own stop bushing for depth of cut.  You start the cut until you hit the stop bushing and the blank rides on the peg in the background.

Jackie Brown has a set that he told me he has been using ever since he started building guns and has never sharpened them once.  No comment!!   

You can also buy molding heads with interchangeable cutters like Dave's and grind the cutters from tool steel.  I opted against that way because if one of the cutters gets loose, it goes right into your gut.

Very often, if you have a furniture or cabinet shop near you, they grind their own profiles and will often do yours for a fee.

Dave we have a place local here that will supply you with the cutters or will make them for you.  It's Southern Woodworking Suppies @ 503 S Second St. Memphis, Tn.  Roy Dexter the owner is a very close friend of mine. 

Jesse

[caliber45]

Guys -- I had a machinist friend make me a bit to cut 13/16ths barrels. Cost me about $25, and works fine. When I needed a 3/4ths bit, he had changed jobs and could no longer do "personal" work. So I made a bit from a spade bit -- cheap-o Chinese spade bit, at that. Made 45-degree angles, removed the point on the bottom, and beveled the cutting edges the same way the "regular" spade bits were beveled. Shortened the shank and hardened/tempered the blade. I use the bit in the vertical mill on my "all-purpose" machine (lathe, etc.; also cheap-o Chinese manufacture . . .). I usually make three passes, igradually increasing depth, so as not to overtax the spade bit. Works wonders. Exceptionally clean on maple, a bit rougher on walnut, but still to "spec." The "throw" on my mill is only about six inches, so I have to move the wood and cut six inches at a time. Keep it straight by clamping the wood between two pieces of angle-iron. Cheap, effective and I don't have to send stock blanks off anywhere and pay somebody big bucks to cut barrel channels.

One warning: Some spade bits (maybe all?) are made "to-width" at the bottom, but taper slightly toward the shank. So, if you cut off the corners as I'm suggesting, your 3/4ths-inch barrel channel cutter bit is going to end up slightly less than 3/4ths inch wide. You'll need to measure the width of the spade bit you want to cut -- up 3/8ths of an inch or so from the bottom -- to be sure the sides of the bit at that point measure 3/4ths (or whatever width of barrel channel you're cutting).

-- paul allen, tucson az

[Dphariss]

Cutter is O-1

Dan

[Clark Badgett]

I haven't tried this either, but would not be inclined to do it.  A typical router hums along at about 25,000 RPM.  A cutter made from a spade bit could easily jamb or take too big a bite and, as I recal, the shanks can be quite soft.

Take it from one who knows.  You haven't lived until you've had a good sized router bit break loose and zip around the shop at 25,000 RPM!!!!!

Laurie

Snap a 4 flute 14mm carbide endmill in a mill sometime as have it zing past your ear at less than 6" and you'll get a thrill you never want to experience again, as well.

[Old Ford2]

It could not be much simpler than # 10 Dphariss' picture of a barrel channel cutter
Thank you for a greant and easy tool.
Old Ford

[David Veith]

Dphariss that is like what I have to but for the upper area. My first ones were made out of V router bits with the end of the V ground down.

[Dphariss]

Dphariss that is like what I have to but for the upper area. My first ones were made out of V router bits with the end of the V ground down.

I made the bit from annealed O-1 then put the assembled cutter in the lathe and cut the angles there so it would cut evenly on each blade.
Then I disassembled, hardened and heat treated the cutter.
I use it in my Jet copy of a Bridgeport.
Dan

[Jim Kibler]

If you don't have a specialized cutter, it is a pretty simple matter to use a combination of straight and 45 degree bits to produce a straight sided barrel inlet.

[VAshooter]

When I was a young sailor too poor to buy a rifle I had to make my own. I cut gunstocks from planks of wood I bought at a lumber yard with a band saw at the base hobby shop and made a fixture to hold them while I cut barrel channels with a router using a modified V bit.  I would grind the bottom off the V and grind the sides in to make the flat dimension and the U shaped fixture with lots of holding bolts would allow me to adjust the angle of the cut and the cast of as well. The top of the fixture was my flat and the back of the fixture held the router true while I cut. I would buy Craftsman router bits and grind them real slow with a pan of water close because I had no knowledge of tempering so I didn't want to mess them up. I had sizes from 13/16th up to 1 1/8th. Haven't done one for a while but the stuff is still sitting in my basement.

I'll sure agree that the router feels like a bomb ready to blow while you are cutting the channels but I never hurt myself or screwed up a gunstock with my system.

Doug

[b bogart]

I've done the same thing as VAshooter. Hog out the channel with appropriate sized straight sided bits, then finish up with the special ground cutters. I've used them a few times and careful use makes for a good barrel channel. Or maybe I have just been lucky???