First spiral fluted barrel I saw was in 1965.
I don't buy Shaw's thinking on spiral flutes benefits.
If it provides more surface area than straight fluting, then it removes more metal; the barrel will be less stiff. Observing the two flute styles in that link tells me there's alot more metal removed by spiral fluting. With the same size flutes, either staight or spiraled, the spiral ones are longer and therefore remove more metal.
"Improved harmonics" is one of the best Snake Oil marketing hypes in the rifle barrel business. There is no benefit of improved harmonics by fluting a barrel by how much metal's removed nor the shape of the barrel afterwords. Removing metal makes the barrel less rigid and it will have a lower natural vibration frequency because it's not as stiff as it was before fluting. Harmonics are just multiples of that frequency. The more metal that's removed makes the natural frequency go lower. And its the same frequency for every shot fired. All that does is change the muzzle axis angle the bullet leaves at. That may or may not improve accuracy for a given load; it might require small change in powder charge weight to get the bullets to leave at the same angle as before. Bottom line's the barrel less stiff with more metal removed and that's counter to what most folks want; stiffer barrels.
Whatever rotational torque the barrel has from the bullet going down the rifled barrel will be exactly the same for every shot fired. Just like the reward recoil from the same thing. Fluting that barrel removes weight so the same amount of rotational torque will have less mass to resist it; fluted barrels twist more in barrel time recoil than non-fluted ones do. As the spiral fluted ones have more metal removed, its lesser mass means it'll twist more from the same amount of torque. But its the same amount each time regardless of how much metal was removed by fluting or whether it was fluted or not; it's consistant with every shot.
It's interesting that the patent was issued in June, 2000, and it's for "The ornamental design for a gun barrel" and the documents state nothing about improving anything regarding his claims on the web site:
http://patentimages.storage.googleapis.com/pdfs/USD426611.pdf
Pro Precision Rifles does spiral fluting that looks like an Easy-Out screw extractor at two places on barrels:
http://proprecisionrifles.com/custombarrelfluting/002b.html
I don't buy Shaw's thinking on spiral flutes benefits.
If it provides more surface area than straight fluting, then it removes more metal; the barrel will be less stiff. Observing the two flute styles in that link tells me there's alot more metal removed by spiral fluting. With the same size flutes, either staight or spiraled, the spiral ones are longer and therefore remove more metal.
"Improved harmonics" is one of the best Snake Oil marketing hypes in the rifle barrel business. There is no benefit of improved harmonics by fluting a barrel by how much metal's removed nor the shape of the barrel afterwords. Removing metal makes the barrel less rigid and it will have a lower natural vibration frequency because it's not as stiff as it was before fluting. Harmonics are just multiples of that frequency. The more metal that's removed makes the natural frequency go lower. And its the same frequency for every shot fired. All that does is change the muzzle axis angle the bullet leaves at. That may or may not improve accuracy for a given load; it might require small change in powder charge weight to get the bullets to leave at the same angle as before. Bottom line's the barrel less stiff with more metal removed and that's counter to what most folks want; stiffer barrels.
Whatever rotational torque the barrel has from the bullet going down the rifled barrel will be exactly the same for every shot fired. Just like the reward recoil from the same thing. Fluting that barrel removes weight so the same amount of rotational torque will have less mass to resist it; fluted barrels twist more in barrel time recoil than non-fluted ones do. As the spiral fluted ones have more metal removed, its lesser mass means it'll twist more from the same amount of torque. But its the same amount each time regardless of how much metal was removed by fluting or whether it was fluted or not; it's consistant with every shot.
It's interesting that the patent was issued in June, 2000, and it's for "The ornamental design for a gun barrel" and the documents state nothing about improving anything regarding his claims on the web site:
http://patentimages.storage.googleapis.com/pdfs/USD426611.pdf
Pro Precision Rifles does spiral fluting that looks like an Easy-Out screw extractor at two places on barrels:
http://proprecisionrifles.com/custombarrelfluting/002b.html
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