Barrel Fluting w/ Vertical Mill

[nitrousmudbogger]

Does anyone use a vertical mill to do their barrel fluting? I was thinking of getting a saw blade style cutter to do some fluting. I saw a cool Haas video the other day of them doing a similar thing cutting splines so I thought why not barrel flutes.
Any ideas on the cutter itself? I wonder if it would need to be supported on the bottom( in a bearing or center of some kind) to keep it from chattering and then just move x&y to get a good flute. What do you guys think?

 

[EddieHarren]

I know of two barrel makers who flute barrels on a vertical mill. Both cut on the side facing the operator. Both have very elaborate follow rest systems on the back side of the barrel to eliminate push-off. Both use flood coolant systems that have large reserves of coolant to keep the operating temp as low as possible. I have had one of these guys flute numerous barrels for me and have never had an issue with any of them. I always have the barrel chambered and fitted before the fluting.

 

[J E Custom]

Does anyone use a vertical mill to do their barrel fluting? I was thinking of getting a saw blade style cutter to do some fluting. I saw a cool Haas video the other day of them doing a similar thing cutting splines so I thought why not barrel flutes.
Any ideas on the cutter itself? I wonder if it would need to be supported on the bottom( in a bearing or center of some kind) to keep it from chattering and then just move x&y to get a good flute. What do you guys think?

There are those that do, and with good skills and a barrel fixture that can hold the barrel perfectly
straight and not allow the barrel to flex at all the results can be OK.

The majority use a horizontal mill because it is pushing down against the bed of the mill and is
very ridged/true.

I still prefer that the barrel maker does the fluting on his own barrels because he has overall
responsibility for the end product quality.

I have some horror stories on barrels that have been fluted after the barrel was chambered
and just won't do it any more because after all the work is don a poor fluting job can ruin a
otherwise great rifle. and the cost of starting over.

I am glad that some have had good luck with fluting after the rifle has been chambered and
head spaced, But my experiences have been all bad and once it is done there is no turning
back.

I know that that was not your question but I though I would warn you of the potential problems
with doing fluting your self. (Not that you can't) just that even the most experienced machinist/
smiths can have trouble with "ANY" process to flute and find out when the rifle is assembled it
will not shoot well after 3 or 4 shots in a row.

I wish someone had warned me. Without exception I had to re barrel every one of the ones
that were fluted after all barrel work was done. and the barrel makers said that they were
not responsible for the barrel if someone else fluted it (It Made sense so I did not complain)
just bought a new barrel and started over,

Just my opinion for what its worth.

J E CUSTOM

 

[lazylabs]

If you have a bridgeport or one of it's clones you can pickup a 90 degree attachment and support bracket for $400 or so on ebay. It will give you the same setup as a horizontal mill.

 

[shortgrass]

Use a couple of large angle plates to support the barrel and the largest shanked cutter you can get with as little of tool over hang (out of the tool holder) as feasible.

 

[nitrousmudbogger]

I have been using the vert mill now but w a ball end mill. It is not exactly the same as say a rem sendero style of flutes. We have it in a Haas vf3 w a 4th axis to turn it in between and jacks under the barrel to support for chatter. The muzzle end is in a small 4" vise. This works well just not the same style flute exactly. Just wondering after I saw that haas vid of them cutting splines(just a different cutting insert but same idea)

 

[Trickymissfit]

I know I'll be hung by my thumbs for this post, but if I just had to flute a barrel, I'd use an arbor with a blade type cutter at a slow speed. Ball end mills tend to create a good bit of stress while making their cuts, but this method is by far the easiest. The mandrel tends to shear the metal in the same direction as the bore. But on the otherhand I would never flute a barrel that's already finished out.
gary

 

[nitrousmudbogger]

Thats what I was thinking. It is the exact same idea as a horizontal if the other end of the blade cutter was supported. This is the vid that sparked my interest. We could do the same on our lathe but think over a long length like a barrel it would chatter hence me wanting to try the mill with some supports.
YouTube - ST-20Y: Turn and Mill Complex Parts

 

[Centre Punch]

You could use a gear cutter mounted on a stub arbour set at centre height and cut into the side of the barrel,
Set up angle plates against the opposite side of the barrel to eliminate flexing as stated by shortgrass.

Ian.