Milling on a tapered round

[cmac]

I have a long tapered round barrel I want to put two side flats on. I could file these I know but I want the flats good and square to the breech. If I put the tang in the vise on my mill the rest of the barrel is about 2" off the bed. What would the best method be to secure this area? Maybe a pipe clamp in another vise(I have 2) mounted to the bed?

The 2 side flats will be about 12" long. I plan to remove .0626(1/16") at breech and 0 at the 12" mark. I have checked and there is plenty of wall thickness to work with. This is for a New England fowler

[chubby]

Hello CMAC, i would use a v block about 12 to 14 inches out from your vise, i would then use a t bolt in one of the slots with a hold down clamp i would also use a pc. of wood between the clamp & barrel to be safe. i would level the bore of the barrel, if your only taking a .062 cut thats not a lot you should be fine! best of luck to ya.  Chubby

[cmac]

Thanks Chubby. I actually just got in from the shop having just milled one side. My setup was just about exactly as described. I did have to cant the muzzle downward a bit to get the taper- checked and double checked that with a dial indicator. I ended up only going with about 9" up from the breech. All came out well, now onto the other side

[Pete G.]

All came out well, now onto the other side

Getting them to match....that's going to be the tricky part. Sort of like trimming one leg of a wobbly table to get it to sit level. After too many attempts you can turn a table into a sitting bench.

[Acer Saccharum]

Depending on the steel, and how much stress in it there is, the tube can bend when metal is taken from one side. Take metal from the opposite side, and it straightens out again.

If you are not aware of this happening, you can take off too much from one side, and have a bent bore.

How do I know about that?

[cmac]

All came out great I can't measure any difference with a dial caliper one side to the other. I was stressing about it at first-if you couldn't tell. After I got my mounts figured out it was just measure, remeasure, remeasure......cut and repeat! My teeth may be shorter now but I'm very happy with the results. Thanks guys