Greg if you have to do it yourself. And you got a indexer and tail stock and enough travel. And know how to use them just do it. Just adjust your tail stock at the right height to give you your taper. Put a end mill in the mill and do it. Then draw file when done. And good luck.

You'll need a angel plate or vice to hold it in the middle otherwise it wont be ridged enough.  I'll also bet your table isnt long enough to take one complete pass. The easiest thing to do is swing the head over to finish  a cut.

I cut a bunch of blanks on my mill when it was new.   

       Joe.

I've got an octagon cutting jig for my mill, but haven't run a machine in over 5 years.  The jig is ingenous, I didn't make it.    

It consists of a heavy flat plate with a bunch of holes tapped into it so that you can attach a tailstock and an indexing head at different distances.  In between the two centers, there is a series of holes tapped in a straight line.   

One center is adjustable for height, so that the taper can be adjusted.  The other is a collet held in an indexing head.   
   
You start by machining a round tenon at the breech end to go into the collet.  Mount the collet and tailstock at the length of the barrel, put the breech tenon in the collet, and put the tailstock center in the muzzle.  Snug the barrel in and adjust the center height for the taper you want.

Now, there are a series of spring loaded pistons that screw into the intermediate holes between the centers.  You let the springs firm the piston up against the barrel underneath it, and then lock them in place.  This supports the barrel rigidly every couple of inches.

In practice, I use a fly cutter and take fairly small cuts.  A large end mill would work as well.  I cut a few passes, then index the barrel over 180 degrees, and reset the spring piston supports.  Make an identical cut to the first.  Now, rotate 90 degrees, cut, rotate 180 degrees, then 45, then 180, etc.

When you have cut all 8 flats the first cut, repeat the process for a few more passes on each flat again.  Repeat until you have it cut to form.

The beauty of this jig is the support.  It keeps the barrel from being bowed under the cutter force.   

I wish I had someone I could permanently lend the jig to near me, with the condition that I could go use it on their mill. It weighs about 140 pounds, and is a pain to set up on my small machine, and I don't have enough travel to use it effectively.  Luckily, I can slide it on my table to cut most barrels in two passes. Draw filing cleans up the overlap.

dave

Dave, that sounds similar to what I've sketched up, except that I plan on using the side of an end mill and supporting the barrel on the off side with angle plates.  That will let me cut a radius to round at the breech end.  My mill is a 10x54" Enco copy of a Bridgy, with about 38" of travel.  Takes time to get all the component parts together to build it!

David

   Good , no great, advice Ohio Sam !

   Bar stock is cheaper to replace than is a rifled barrel blank .

   Creedmoormatch

I use angle blocks in a horizontal mill to take the vibrations out and keep the barrel from pushing away from the cutter. You can do the same with clamps and blocks with an end mill. You will want a cutter about 2"-2.5" in diameter if you want the Sharps stile tulips. Most tapers for Winchester barrels are around .050" per side for the length of the barrel. A barrel with 1.060" across the flats at the chamber end should be close to .960" at the muzzle. You can give it more taper if you like the barrel light at the muzzle.

Dave sure too bad postage is so high..Been wanting to see that ever since you told me about it sometime ago. Maybe one day I will have to go to S.Dak.  Whitey