View Full Version : Straight fluting

Curley Red
02-18-2012, 7:52 PM
Other than weight loss is there any advantage or disadvantage of it? I've ordered a WOA varmint 20" and was wondering if it is worth the extra hundred. Once I get my barrel I get to build my first AR, I have all the other parts now I'm just waiting for my barrel.

02-18-2012, 8:24 PM
Better heat dissipation and improved stiffness of barrel.


02-18-2012, 8:30 PM
Fluting a barrel dioes not make it stiffer than the full diameter barrel that it started out as. A fluted barrel will be stiffer than a smaller diameter barrel of the same weight.

02-18-2012, 8:31 PM
Considering the length, you may not gain that much.
You will shed very little weight, but gain rigidity.
However, the fluting would be disrupted in the area before and after the gas block journal. So your rigidy would be interrupted in the gas block area.
Plus the bullet weight of the .223 really won't give the barrel enough whip, where you would benefit from the extra rigidity.
My opinion is that would not be worth it.
If it was an AR-10 barrel with a larger bullet causing more whip, or a longer AR-15 barrel, say 24", then it might be worth it.

02-18-2012, 8:33 PM
Whiteoak does some good flutting work


Curley Red
02-18-2012, 8:37 PM
Thanks Wardog, I was kind of thinking what you said.

The Virus
02-18-2012, 8:55 PM
fluting does NOT increase rigidity, it is removing material therefore reducing rigidity.
It is done to decrease weight while maintaining good rigidity, but it simply cannot increase the rigidity.

02-18-2012, 10:11 PM
Uh Oh.
The discussion begins.
This is one of the sources that I use to offer an opinion.
"Fluting the baseline barrel showed a reduction in group size of about 21%. Keeping the same weight and fluting the barrel with a 1.222" muzzle diameter reduced the group size by 23%. If fluting is done without introducing large residual stresses in the barrel it should improve accuracy by as much as 20% over a solid barrel of the same contour."
An excellent read: http://varmintal.com/aflut.htm
Al approaches gun myths scientifically, and records the experiment results as such.
While I flute barrels for customers, I personally don't think it is worth the time or money for the results. I have seen known accurate unfluted shooters lose their accuracy after fluting, but I have also seen improvements in accuracy. However being a handloader, and understanding the dynamics of a barrel under pressure, some of the accuracy loss may be made up with different loads, or finding the relocated 'node' of the barrel for the given ammunition.
I have acouple of heavy barreled, amazing shooters, that are so accurate that I wouldn't even think about fluting them with the risk of losing the accuracy. Besides they are so heavy, the minimal weight shaved is not worth the time since I am not running around with them. They are Bench guns not carbines.
I think most customers who want the fluting have it done for the tacti-cool look.
The fluting argument is similar to cryo treating barrels.

02-18-2012, 10:18 PM
Great info Wardog, I would agree that most people do them for the look over function. Have you looked into any differences in spiral fluting vs. straight fluting? What do you feel the advantage is to the fluting on the bolt of the rifle?

02-18-2012, 10:35 PM
... Have you looked into any differences in spiral fluting vs. straight fluting? What do you feel the advantage is to the fluting on the bolt of the rifle?

I have NOT researched spiral fluting.
I actually run a Pratt & Whitney Sine Bar Rifler (Cut rifling) and cannot wrap my head around any benefit for spiral fluting and how it doesn't adversly warp the barrel.
I have also cut spiral into bolts. I see NO benefit other than trimming a few ounces of weight, and maybe the dispersal of dirt in a very dirty environment. I think it is also cosmetic. The locking lugs are the only vital part in battery, the spiral flutes aren't contacting anything.

I think Al's website is a goldmine of scientific conclusions to pondered questions about guns and ammo. I check there often but never use it as a sole source of information.