Re: vibration node Q
Here's Jim Ristows response
1) The barrel moves in what I can only describe as a 3 dimensional wave. The amplitude is of course affected by profile, thickness and length.
2) It is caused by the mass of the bullet being accelerated into a twist. The rate of acceleration and twist determines the frequency.
3) Imagine a smooth bore with all rifle mass in line so there is no muzzle rise. There would be no harmonics just slight "ringing". Two entirely different issues.
4) Shorter and thicker barrels are more rigid with less muzzle movement but it is still there. In practical application the nodes (where it will shoot) are simply wider. A "Whippy" barrel is less tolerant of ES and nodes are narrower.
5) Where the barrel shoots best the muzzle is at the extremity of swing, not at the static location....this is the nugget of info that should bring it all together. You can prove this yourself by loading a long thin barrel to several nodes and shooting at the same 100 yard aim point (utra lights are perfect for this). Often lower velocity nodes will shoot up and to the side. I have seen 9 or 10 inches between groups (most only 4 to 5) which proves at least 4 or 5 minutes of muzzle swing on thinner barrels.
[img]images/icons/smile.gif[/img] Hope this helped
Distance is not an issue, but the wind will make it interesting!