Red_SC
Member
Clipper,
There's nothing you can do to a bar with a mill that will make it stronger- you would have to make the lands farther from the center of the bar, which fluting can't do. Since you're a machinist, it will be easy for you to prove or disprove this one. Put a bar in a fixture, put a dial indicator on it, put a weight on the end, and measure the deflection. Then, mill flutes into the bar and try it again. I'd do this test for you, but I'm a computer programmer that has never seen a mill.
Seriously, since you're a machinist this would be easy for you to do. Since a barrel's harmonics are in an oval not just up and down, do it with both the flutes and the lands on top.
Let me see if I can explain this one from the other direction- I even made a picture using my mad MS Paint skillz. In the pic below, the left pic would be a cross secton of a fluted barrel. When the barrel flexes up and down, the top and bottom flutes will expand slightly and the side flutes contract slightly. A similar thing would happen with an odd number of flutes.
Imagine if we were to add in some extra ribs into the flutes- without question, this would be stiffer than the left crossection. For the barrel to flex down, the bottom ribs would have to be compressed and the top ribs expanded in addition to bending the original barrel. The left and right ribs wouldn't add much strength at all, since they have little strength in this direction. When the bar flexed up or down, the side flutes would still close in a little. The side ribs would help with side to side flexing, though.
Now, imagine that we fill in the gaps between the little ribs, like the third pic. Again, this one will be stronger than the previous one. In addition to bending the original barrel, it would also have to bend the ribs and the material between the ribs. Also, the gap caused by the side flutes can't close in anymore, so it's even stiffer. It's also a round unfluted barrel.
If you follow this logic, it makes sense that a round barrel is stiffer. If you can't, try it yourself. You can't make a barrel stronger by removing material. In case you're really a machinist and understand what you're machining, I do know I'm wrong in one area, stress risers, but that's not really part of this discussion. 'Sides, that discussion would prove my point, too. Fluted barrels are stiffer than unfluted barrels of identical weight because some of the steel is farther from the center of the barrel, making a larger cross section; however, a fluted barrel is less stiff than an unfluted barrel of identical diameter.
There's nothing you can do to a bar with a mill that will make it stronger- you would have to make the lands farther from the center of the bar, which fluting can't do. Since you're a machinist, it will be easy for you to prove or disprove this one. Put a bar in a fixture, put a dial indicator on it, put a weight on the end, and measure the deflection. Then, mill flutes into the bar and try it again. I'd do this test for you, but I'm a computer programmer that has never seen a mill.
Seriously, since you're a machinist this would be easy for you to do. Since a barrel's harmonics are in an oval not just up and down, do it with both the flutes and the lands on top.Let me see if I can explain this one from the other direction- I even made a picture using my mad MS Paint skillz. In the pic below, the left pic would be a cross secton of a fluted barrel. When the barrel flexes up and down, the top and bottom flutes will expand slightly and the side flutes contract slightly. A similar thing would happen with an odd number of flutes.
Imagine if we were to add in some extra ribs into the flutes- without question, this would be stiffer than the left crossection. For the barrel to flex down, the bottom ribs would have to be compressed and the top ribs expanded in addition to bending the original barrel. The left and right ribs wouldn't add much strength at all, since they have little strength in this direction. When the bar flexed up or down, the side flutes would still close in a little. The side ribs would help with side to side flexing, though.
Now, imagine that we fill in the gaps between the little ribs, like the third pic. Again, this one will be stronger than the previous one. In addition to bending the original barrel, it would also have to bend the ribs and the material between the ribs. Also, the gap caused by the side flutes can't close in anymore, so it's even stiffer. It's also a round unfluted barrel.
If you follow this logic, it makes sense that a round barrel is stiffer. If you can't, try it yourself. You can't make a barrel stronger by removing material. In case you're really a machinist and understand what you're machining, I do know I'm wrong in one area, stress risers, but that's not really part of this discussion. 'Sides, that discussion would prove my point, too. Fluted barrels are stiffer than unfluted barrels of identical weight because some of the steel is farther from the center of the barrel, making a larger cross section; however, a fluted barrel is less stiff than an unfluted barrel of identical diameter.
