Dave,

Thanks for taking the photos and posting them.  That certainly is a clever setup.

Wayne

John, I like the Sharps tulips in your pic. I was going to bring the flats right out to the frame, (not nice) Am putting a .22 WMR on a low-wall and I thought the .600 muzzle would look OK. I will leave about 2in round at the breech now and run the flats into the round. Am going to use a bridgeport with a long table and about a 3/4in end mill and use it as an end mill and not side mill it. Will use a vice in the middle like you do. Thanks for you help
Greg

SSDave

Thanks for posting pics.   
I make a few oct bbls here in the shop, and have been thinking about building another fixture or improving my setup.  I like the “spring loaded, locking stop” idea.  But my concern/question is, how much movement do you get in the barrel when machining, since the barrel is only held in at two points?   

Thanks

Mike Hunter
Hunter Restorations
(You need to Login or Register to view media files and links)

Mike,

I don't have a good answer for you, as I only cut one entire barrel on it before deciding I needed a better machine with more travel.  Sliding the jig on the table introduces enough error into the cut that it takes some draw filing to clean up the interface between the two cuts.

I used a fly cutter, and the side supports were used to keep the barrel from springing away from the direction of rotation, as well as the bottom ones keeping it from bowing down.  The interrupted cut of a fly cutter generates a lot of vibration, but the pegs stopped that pretty well.  Adding a clamp in the middle like John has would be an improvement.

I have used the jig also to octagon rolling block receivers.  It works well for that, as I have a mandrel I screw all the way through the receiver, mount one end in the collet and the other in the center.  I use a half inch carbide end mill for that operation.  I think it would also work relatively well for fluting barrels if a person was to get into the tacticool business.

I really should pass the jig on to someone else, as I will likely never buy a bigger mill and do any serious machining again.  I went back to working a regular job for a living, and have close to 15 years before I can retire from that, and no guaranteee that I'll be interested in machine work when I have time again.   

I have Paul Shuttleworth octagon barrels for me, or buy them that way.  Same as I have Montana or McGowen turn and polish round barrels for me.  I'd rather do that than clean up the lathe after I get sanding grit all over it.  I send them a cad drawing of the profile I want, they plug it into the CNC and $30 plus $15 postage later it comes back to me perfect.  Plus, I don't have my lathe set up at the moment anyway.  As long as there's great craftsman like John Taylor and John King that will do work in a reasonable time frame, I'm better off keeping my gunsmithing tools confined to a couple of screw drivers and a dremel tool.

dave

Here is a more resent thread on octagon barrels:

(You need to Login or Register to view media files and links)

Frank