help with fluting question

[dogdinger]

i just finished my first rifle build, and not knowing much about contours etc, i ended up with a really heavy douglas stainless bbl. the gun shoots wonderfully well , but i would like to have the barrel fluted to drop a little weight. any of you smiths out there have experience with this and an opinion on whether it will affect accuracy? does the barrel have to be removed or can it be done on the action? thanks in advance for any responses. AJ

 

[lazylabs]

Fluting is best done before the final interior dimensions of the barrel are established. The cut rifled guys will fluting before reaming. The button guys usually flute before lapping. It can be done after a barrel is fitted but COULD really change the way it shoots. That's my take on it anyway... I am sure you will a lot of feedback on this.

 

[specweldtom]

Fluting is best done before the final interior dimensions of the barrel are established. The cut rifled guys will fluting before reaming. The button guys usually flute before lapping. It can be done after a barrel is fitted but COULD really change the way it shoots. That's my take on it anyway... I am sure you will a lot of feedback on this.

Ditto. From what I have read on the subject, I would buy a barrel that was fluted by the barrel maker, but not flute one after it was finished and mounted.

Tom

 

[NesikaChad]

I've fluted finished barrels before.

Not hundreds of them, but quite a few in a variety of brands, contours, and calibers.

I've yet to have one "go south" on me. The procedure is important. Take a big snorty cut and you are liable to generate some heat and a significant amount of stress removal all at one time. Its reasonable to assume then that the bore dimensions alter slightly and the gun is now prone to shooting poorly.

So. . .

Take smaller cuts and run it over a few passes and it seems to work fine. least that's been my experience. I change locations every pass and work 180 degrees from the previous cut. Cutter selection also makes a difference. I never use a ball end mill. No matter what spindle speed the tool is at, the center isn't turning. This means it's not cutting as it has no surface speed. It's deforming the material or "peening" it. you can see this because the tool marks will leave a slight line at the root of the flute. I cannot help but feel that induces stress as it'd be no different than if I took a hammer and punch and peened the barrel all over the place. Displacing metal introduces stress just like cutting on it does.

I use a profiled key type cutter and work on the side of the barrel. It complicates sets up a little since the machine is a vertical mill, but with a little thought it can be done without too much head scratching. A 4th axis certainly makes life easier too.

Several well established barrel makers will flute a barrel that is finished. If they can do it, it's stands to reason that others can too.

Good luck.

 

[Boss Hoss]

If done by someone who knows what they are doing it is not an issue no matter what well meaning people here tell you. The makers all say that because the potential to screw it up and add stress or relieve stress, or cut too deep.

World records have been shot by my HOF BR Shooter and Smith with button tubes he fluted. All of my tubes competition or sporters are fluted, buttoned or rifled by him with no issues ever over a period of years.

Just make sure you are dealing with a world class Smith who knows what the devil he is doing and there is no problem.