I know the subject of barrel fluting has been flogged to death, and I apologise if this question has already been raised, but my action and barrel are about to go off to the gunsmith within the week and I need to make a decison on whether to go fluted or not.

Is it a good choice to get a barrel fluted after it has been manufactured? I have read that Shilen won't guarantee a barrel blank if it is fluted by a third party

I have had a PacNor 6mm x 284 Super Match that was fluted and shot constant 0.25 MOA, and a Kimber Pro varmint .204 that was also fluted and shot between 0.25 and 0.5 MOA. So I know from personal experience that they are accurate.

In the case of the PacNor, I am pretty sure that they fluted my barrel before the rifling process took place (seems to be the case from what i read about any barrel maker). The Kimber, don't know so I can't comment.

I really like the look of the Flutes (its purely aesthetic's for me for fluting and some weight savings as well). However if it is not a recommended practice to flute after the barrel has been manufactured and could result in poor grouping then I'll stay away from it.

The barrel is a 6.5mm Krieger Criterion blank, that will need to be contoured.

Many thanks,

Michael.

The thing is that machining can put stresses into the barrel and this may adversley effect accuracy.
Careful choice of a fluter and perhaps a stress relieving heat treat after machining would help.

I've fluted quite a few but haven't done one in at least five years. I never experienced a problem with a barrel post fluting and other than perhaps cutting them too deep don't know of anyone who experienced issues caused by fluting. I congratulate you on your understanding that it is purely a cosmetic thing.

since you say the barrel still has to be contoured then the stresses of machining flutes are the least of your concerns. the contouring adds its own issues.

I have actually fluted quite a few barrels. I don't like the idea of fluting them and possibly its because of all the horror stories that I have heard, but I can't say that I have ever had one go bad myself. I think possibly that I only got into it in the last 20 years or so after barrel makers started stress reliving their material. I have had a few go wonky on me when turning them or octagon tapering, but again, that was 30 years ago. The steel has gotten a lot better in the last few years.

Just off on one of my regular tangents here. But I have started doing 12 spline instead of the common 5, 6 and 8. It doesn't remove anymore material than conventional fluting but it looks really Buck Rogers to me.

I always get confused by these threads, it is my understanding that barrel manufacturers rifle a blank then contour and if flutes are required it is then fluted.
But some how if the barrel is shipped from the manufacturer then anything that is done to it imparts "stress" on the barrel(?) such as re contouring or flutes....
I've always had a hard time buying the phenomenon.
My personal opinion is that a gunsmith can contour a barrel or flute it without imparting any more stress on it than the original manufacturer would have doing the same process, no mystery no smoke and mirrors.
Some will counter my opinion with an argument that if you have a barrel that shoots accurately and you re contour it or flute it that it may not shoot as well because you have unleashed hidden "stress" in the barrel causing it to wildly throw the bullets. Again my personal opinion is that if that barrel was going to shoot like that it would have done it if the manufacturer did it or another qualified party and I feel it is more a matter harmonics than much else.
Your opinion will most likely differ but I'll stay with mine...

Spearchucker I posted my post while you were posting yours, had not read yours, no offenses intended...
By the way the 12 flutes are interesting, I like them.

Well there is actually two types of stress to be concerned with when fluting or turning.

The first is residual stress left over from the manufacturing. If that is present in the material, the material will actually warp or twist around as you remove material. This can cause the barrel to bend or warp as you cut it and it can also cause your flutes or flats (if you are octagoning) to go all wonky. I have found that this problem has almost magically disappeared in the last 15 years. Oddly enough, this coincides nicely with when barrel makers started double stress reliving. So that makes sense.

The second is added stress. Any time you work or cut material you run the risk of adding stresses by bending or surface hardening it.

There are possible ways to get around, or minimize this phenomenon. These are my own personal beliefs, so you can take them with a grain of salt or explore them farther if you want.

I finally came to the conclusion that ball mills tend to work harden the surface a lot and dropped them in favor of convex cutters, sprocket cutters or involute gear cutters. I also dropped my go-to carbide cutters which also cut harder and work harden the surface in favor of the less durable but sharper and easier cutting HSS cutters. I always use a steady rest now when I flute. This creates dead solid back pressure on the barrel to offset the force of the cutter which I believe might help relive stressing the material. Doing this obviously creates a chatter condition as the material sets up a harmonic from the cutter teeth pushing the barrel into the steady. I beat the chatter that this creates by piling 40 to 60 pounds of bulk lead against the cutter side of the material to soak up and break vibration and chatter that can stress the material. Also, I run a full flood of water on the cutter not only because I have to, to preserve cutter life, but it also keeps the barrel dead cold while working. Lastly I resharpen my cutters often to keep tool pressure down to a minimum.

I'm not saying that this is the end all and the only way to do it, but it has been working for me.

Never had a problem with fluting as I only use barrels that have been stress relieved correctly.
Fluting is a useless exercise and I only do it if the customer insists on it, for cosmetic reasons only.
I prefer the original Mauser contour, no fluting required.

It's always safer and cheaper to turn to reduce weight rather than flute. But fluting does look cool and I'm a whore. I have bills to pay and I will do anything for money. As long as it's enough money and as long as the gubberment doesn't have a problem with it.

Thank you everyone here for your opinions

I've sent an email off to Criterion themselves to ask their opinion as well. I may in the end make a decision not to flute and it will probably come down to the cost issue as it is another $300.00 for something pretty much cosmetic.

A No. 2 or even a No.3 countour barrel is still going to mean I end up with a reasonably light rifle, certainly within my weight limits I have decided on.

I will venture that I have probably milled, ground, edm'd and welded more than some as a 28 year Plastc Injection Mold Maker....literaly tons

All metal no mater if it's Amco bronze, Beryllium copper or any tool steel you wish to name has stress imparted in it during it's manufacturing process

When it is machined stress is rarely added but more so it is changed by removing stock "relieved"

Stress is then changed during heat treat and draw and cryro

Stress is intoduced in a greater extent by welding but this is different subject all together

No matter what you do.....you remove stock things will and can move because of inharent stress not syress you impart

Contouring,flutes,octagonal flats,integral features, etc
not much of an issue if one bores,reams and cuts the rifling after any/or all of that stuff is done.

However, very few people do it that way.

quote:

A No. 2 or even a No.3 countour barrel is still going to mean I end up with a reasonably light rifle, certainly within my weight limits I have decided on.

Just put together a spreadsheet with all of the rifle components and their weights. If I was to go for a number 3 contour, 24 inch unfluted barrel, I would be looking at a total overall weight of 7.6 lbs fully loaded including scope & mounts, which is well within my weight limit.

And that $300.00 for fluting? Well, that will pay for the Cerakote.

Fluting does actually have some practical potential. If you intended to go with a cartridge like 6x45mm or even 308 and want a medium weight you can start with a number 6 or 7 conture barrel, cut it to 18 inches and flute it down to a minimum ID. I have done this on a few rifles and once you get used to how weird they look, they make incredibly stiff and good shooting barrels that weigh in about the same as a number 3 weight, 24 inch barrel. But, you need to start with an anemic cartridge that operates best in short barrels to begin with. In these days of Rambo and tacti-cool you don't see to many of those at the range. LOL

I've fluted a few in the past and will continue to do so. Usually it's just to change the handling and change the balance to the rear a bit. The last one was a 6.5 RSAUM on a model seven action with a #3 that finished off at 7lbs. Just wasn't what we were looking for and after a pretty aggressive 6 flute and fluting the bolt it ended up at 6.5 lbs and balanced perfectly. It shoots VERY close to 1/2 MOA, easily under 3/4 MOA and my buddy has exactly what he was wanting.

quote:

Originally posted by matt salm:
I've fluted a few in the past and will continue to do so. Usually it's just to change the handling and change the balance to the rear a bit. The last one was a 6.5 RSAUM on a model seven action with a #3 that finished off at 7lbs. Just wasn't what we were looking for and after a pretty aggressive 6 flute and fluting the bolt it ended up at 6.5 lbs and balanced perfectly. It shoots VERY close to 1/2 MOA, easily under 3/4 MOA and my buddy has exactly what he was wanting.

Just for giggles Matt. When you flute a barrel do a quick chunk of aluminum in your lathe to the muzzle diameter of the barrel you just fluted and the end turned to the .550 inch minimum. Then flute the first couple of inches of it while the mill is still set up by just clamping it into the spacer or dividing head. They only take 10 minutes to make and are good examples to show customers later.

The one shown is a .840 muzzle Shilen 7 LV Light Varmint [2] conture.
I don't know if 12 splines actually eats up any more material or is any stiffer than 6. You would need an engineer to figure that crap out, especially if you cheat like in this case where the land is .090 inch and the groove is .126 inch. But it sure does look fawkin nasty and appearance is 90% of custom gun work.

I did recently do a combination of 12 flute and 6 flute on an AR10 barrel. 12 fluted the rear portion and 6 fluted the barrel ahead of the gas block as the diameter wasn't large enough to have enough web on a 12'er. He wanted it 'light'.

I usually go in batches, right now I have to get two more barrels finished, then I'll set up the mill and flute the 6 barrels needed. If I have a button barrel and the borescope shows less than stellar interior finish I'll flute the barrel before chambering and cast a lap and re-lap the bore before thread/chambering/cut/crowning. Might not make a spit of difference but if there was any changes in the bore on a small scale the lapping might just even up some of that. Some very good barrelmakers which happen to be close friends led me along and showed me the lapping process and at times I'll just get the rifled blank with no final lap from them and finish it myself...saves them time and they shoot just as good...one of them did provide me with his special 'sauce' to use though.

I tried doing some stuff in batches like fluting, bolt handles, recoil pads and barrel and chamber work. But I finally said to hell with it. On general stuff I like to get it in and out of the shop in 4 days. I charge for the machine setup time now and I'm usually $50 to $100 more expensive than my competitors but the guys get them back in four days and I weed out a lot of the cheapskates. It's been working for 5 years and I do get some price whiners, but I'd rather not deal with them anyway.

With barrel work I now tell the guys to buy their own barrels pre contoured and if it's a caliber I don't have I tell them to buy the reamer and gauge for it as well. I finally decided that I'm not a reamer collector and I sold all of my oddballs and most wildcats.

Everybody and their dog is a barrel supplier now days and the customer can save $100 ordering the barrel himself. I have a two week policy on barrel installs because I generally need 2 or 3 machines free for the job, there is always stupid stuff like inletting and bedding involved and I have to clean up my 4 days backlog to waste a day or two on the barrel job. I charge the same as Gordy Gritters which is a bit high but they do get their gun back in one or two weeks which is sometimes two months faster than my competitors.

Not that this policy would work for everyone. But it works for me and I don't get thirty: "is my gun done yet?" phone calls every day.

I try to get work out asap, but it's not worked out that way in the last year. I do this part-time with a full-time job besides. I enjoy the work and it pays for a lot of my own toys. My customers know my timeframes and are still getting their work back sooner than most other places. Many of them are semi-local and they appreciate being able to stop by and pick it up and talk over the work done or work to do. There are those that want to look over my shoulder while doing the work and I tell every one of them that the ONLY time I've 'phucked something up was when I was answering questions or explaining something while trying to do the job... They usually get the idea.

Setting up for fluting is really not a big deal, but I put it off until I have several and then just get it over with. Turn-around can be as little as a weekend, or it is just sometime 'before hunting season'. My job board has filled up though and I need to get in the shop more. Tough with a 5 month old child at home I'm learning!

There are days when I get the urge to just say to hell with it and do this as a hobby. But then I realize that I would have to go out and get a real job with a boss that I couldn't tell to go to hell if I disliked him or couldn't stand the color of his shirt and for some reason the urge passes. It's a very perplexing and confuzzling predicament dontchaknows.

quote:

Originally posted by speerchucker30x378:
I tried doing some stuff in batches like fluting, bolt handles, recoil pads and barrel and chamber work. But I finally said to hell with it. On general stuff I like to get it in and out of the shop in 4 days. I charge for the machine setup time now and I'm usually $50 to $100 more expensive than my competitors but the guys get them back in four days and I weed out a lot of the cheapskates. It's been working for 5 years and I do get some price whiners, but I'd rather not deal with them anyway.

With barrel work I now tell the guys to buy their own barrels pre contoured and if it's a caliber I don't have I tell them to buy the reamer and gauge for it as well. I finally decided that I'm not a reamer collector and I sold all of my oddballs and most wildcats.

Everybody and their dog is a barrel supplier now days and the customer can save $100 ordering the barrel himself. I have a two week policy on barrel installs because I generally need 2 or 3 machines free for the job, there is always stupid stuff like inletting and bedding involved and I have to clean up my 4 days backlog to waste a day or two on the barrel job. I charge the same as Gordy Gritters which is a bit high but they do get their gun back in one or two weeks which is sometimes two months faster than my competitors.

Not that this policy would work for everyone. But it works for me and I don't get thirty: "is my gun done yet?" phone calls every day.

My kind of business model! I wish there where more Gunsmiths and Taxidermists that thought that way!

.