I have a Bartlein 6.5 heavy varmint blank on the way to have screwed onto a a Remington 700 which will be chambered in .260 Remington. What are the pros/cons to fluting? Is the heavy varmint contour thick enough to flute?
I'll admit to thinking fluting looks cool but I don't know if the cooling properties are enough to justify getting it done especially if there are any drawbacks I'm not aware of.
What are the pros/cons of fluting?
Benchrest and scare tactics.
Early on in this trade it was impressed upon me by sacred cows of the benchrest community that it took some sort of magical divine intervention to flute a barrel w/o ruining it. The benchrest community has always enjoyed a sort of "final word" stature amongst us gun nuts. How do you argue with a rifle that puts 5 shots inside the diameter of a pencil eraser right? It was beaten into my thick skull so hard that I avoided it all together.
As time wore on more and more guys started fluting barrels and slowly the "cardinal fiction" changed.
Bottom line is this:
Fluting (done well) looks really cool.
It does make the barrel weigh less than what it did prior to fluting.
That's all it does. The barrel was as stiff as it was ever going to be prior to fluting it. Cutting away material didn't suddenly make it stiffer.
It does offer more surface area than one that does not have flutes. Just as fins on a lawn mower aid in convection, so will this increase in surface area on your barrel. But know that its at the expense of reducing the "soak" time (my word that I made up) that it takes for the barrel to heat up. It takes less heat to make a little piece of wire glow than it does a 1" piece of rebar. MASS is what your dealing with. Not SHAPES.
If the expense of having it done makes sense to you, then by all means do it. Pick a shop that's reputable for this service.
Fwiw I've fluted quite a few now here in our facility. That last two weeks have resulted in some very long weekends and late nights as I completely changed how I used to do it. The result of that hard work has been extremely rewarding.
Here's one I ran late yesterday afternoon. The smaller barrel is a factory M700 take off. The larger is a new Bartlein. You'll hear things like causing stress in the steel, etc. . . when having this done on an existing barrel. Ignore them as its from folks who don't fully understand what machining metal actually does. Your not causing stress, your removing it.
A simple analogy: Make a ball out of rubber bands. Everything is stretched and pulled; its full of "inner turmoil." Now take a pair of small scissors and snip at random bits here and there till you have all the bands cut at least once. This is what machining does. The stress is gone, there's just no assurance that the ball is still a sphere. It might very well take on the shape of an egg now instead.
BUT if we were to remove all/most of the tension in the bands by some magical process (heat is a pretty good one, so is extreme cold) prior to cutting them then we would have a reasonable expectation that our ball would still look like a ball when we attacked it with the scissors. -right??
The key here is getting the steel properly "normalized" before hand. (aka- stress relieved) Normalizing aligns all the little grains/molecules/whatever in the steel. It goes a long way towards removing this stress. If the stress is already gone, then cutting on it won't somehow create it from thin air. It'll just put grooves in the steel which is all your really after. This is something barrel makers do as a standard part of their manufacturing. It's been done for decades now and they know what they are doing. You don't have to fret over it.
If you dig around and read the internet there's various stories about how it should be done. The "tool and die" (blech!) makers will likely tell you that you must take extremely light cuts and not put ANY heat in the barrel as you machine it. -cause you'll induce "stress". (right about the time you read this is when the urge to place the Glock in your mouth starts to take over)
I've PROVEN that you don't have to take multiple light cuts. I flute our barrels at over 900SFM (Surface Feet per Minute) DRY with no coolant and a .005"/tooth chip load! (This is machinist vernacular for "Chad doesn't F$ck around when fluting a barrel") The chips are blue hot when they fly off. The barrel is luke warm at best when I'm done. The noise inside the shop as it cuts again compells you to reach for the pistol. They come out of the machine completely finished. No 2ndary operations required. The key is choosing the right tooling, the right inserts, and developing the proper fixturing so that you can push your machines to operate at a level they are designed for. Modern tooling is nothing short of amazing. The fancy coatings they apply to inserts truly are worth every penny.
Bottom line. Have it done if you want to and fear not.
Good luck and happy 4th.
C.
PS: The engraving is Wylie Coyote w/the Ghost buster circle/slash line thingy through the middle. This barrel is for a local guy who has a serious morbid hatred for coyotes.
(James Oneill of OneillOps.com)
