11 March 2003, 17:47
Recoil RobAre octagon barrels any stiffer (more accurate) than the same weight round barrels?
By weight I mean weight class or barrel contour for lack of a better term.
Are fluted barrels really stiffer?
Does more stiffness translate to better accuracy?
thanks, rob
[ 03-11-2003, 08:47: Message edited by: Recoil Rob ]11 March 2003, 18:04
<Loren>There are more important contributors to barrel accuracy than stiffness.
The metal farthest out from the center of the barrel contributes most to stiffness. For a given amount of metal getting more of it out farther from the center helps with stiffnes, so yes, an octagonal barrel (or fluted) of similar dimensions and weight would be somewhat stiffer.
My guess is that given the same amount of attention the non fluted or round barrel would be more accurate. Fluting or putting flats on a barrel is an operation that has potetial to cause problems if not done uniformly. Turning something to a round profile is easier than machining flats or flutes.
12 March 2003, 13:03
<Buliwyf>An octagon barrel is beautiful to my eye and definitely has the capability of being very accurate.
However, an octagon barrel is several times more expensive than a round barrel and there is more risk of the octagon barrel being less accurate than a round barrel. A round barrel is turned symetrical with the bore during manufacture while complicated machining is required to complete the octagon barrel. Differences in thickness of the octagon cuts and improper stress relieving can negatively effect accuracy. Same scenario is true with a fluted barrel compared to a round barrel. Selecting experienced people is key. I won't say competitive benchrest or olympic rifles don't employ octagon or fluted barrels, but the ones I have seen use round barrels.
With that said, my choice for a custom rifle would be an octagon or hexagon barreled .416 Hoffman.
Buliwyf
12 March 2003, 14:01
Recoil RobWell, I'm considering having my M1999 SS action barreled by Montana rifle in an Octagon, I have to think they'll do it right.
rob
12 March 2003, 14:28
Chuck NelsonI know an older gentleman who "octagon's" his own barrels with a horse rasp. He actually does an excellent job, and when he told me how he did it my jaw about hit the floor. I don't know how it affected accuracy but he sure liked the weight it removed.
Chuck
12 March 2003, 15:38
Bill LeeperChuck,
I think Eddie roughed the flats with a bench grinder then went to the files.
13 March 2003, 07:47
edi malinaricDon't knock handwork. A friend of mine successfully filed his bigend journals down to 0.010" undersize. A micrometer couldn't fault his work. When you're broke and the oil pressure is low!
I have proved to myself more than once that I can do precision work by hand with only hand tools.
When carrying out preparatory work for the repair of composite sailplanes my party trick is to bevel the scarf joint, all the way to completion of the joint face, using a 10" angle grinder . In the field when there was no electricity I achieved the same effect with nothing more than a broken piece of power hacksaw blade. Just took longer.
Some of the hand fitting trade tests of yesteryear were quite mind boggling.
Take a square bar and file it until it is 1.000" in diameter, file a 1.000" square hole so that the round bar touches all four faces and slips through, file the faces of the round bar square and parallel - 1.000" so that it is a light tight fit in the 1.000" square hole.
Tolerances? You don't achieve a light tight fit with tolerances.
How did I do? Not too well. I was 0.0005" under on the round. OK on the square hole and end faces of the round. OK meant that the micrometer witness lines weren't more than half a line thickness either side of absolutely in line.
Happy Days - cheers edi
13 March 2003, 08:55
Chuck NelsonBill, this was actually an untrained do it yourself kind of a deal. He just sat down in the living room with a rasp and went to work. His name has just escaped me, but he was working on his own rifles built by Ron Prop.
Chuck
13 March 2003, 09:05
Chuck NelsonBill, his name is Vance Allred and I just talked to someone who actually shot one of these rifles, and he said they couldn't get the thing to shoot.
Chuck
13 March 2003, 17:42
<Buliwyf>Good for you Rob. Let us know how it turns out.