Blaine Fields
Well-Known Member
I have a question that produced a lot of heat on another precision shooting site, but not a lot of light. The question is whether 30 caliber bullets are tractable or not.
Tractability is the property that allows the longatudinal axis of a projectile to remain tangent to the trajectory. In other words, a bullet may have a positive angle of attack relative to the ground as it exits the muzzle, then become level at the apex of the trajectory and finally nose over as it heads downward toward the target. Picture a well thrown football to get a perfect picture of tractability.
According to one correspondent, bullets are not tractable. He believes that whatever angle the bullet has at the muzzle the bullet will retain throughout its flight. In otherwords, the longitudinal axis of the bullet remains fixed in space from muzzle to target; it doesn't nose over. I have been unable to obtain any source supporting this view from this particular person, however.
In contrast, I believe that a bullet that is just stable at the muzzle, i.e., not overspun or over-stabalized, will follow its trajectory like a well thrown football. However, other than a mathematical reference to tractability (see this web page), I can't find any source material supporting my belief either.
Does anyone have an informed view concerning this matter? The issue is of some import, especially for long range shooting, since it impacts directly upon the aerodynamic efficiency of the bullet. If a bullet's axis is fixed in space, one would expect higher drag as the bullet began to expose a greater area to the relative wind.
Tractability is the property that allows the longatudinal axis of a projectile to remain tangent to the trajectory. In other words, a bullet may have a positive angle of attack relative to the ground as it exits the muzzle, then become level at the apex of the trajectory and finally nose over as it heads downward toward the target. Picture a well thrown football to get a perfect picture of tractability.
According to one correspondent, bullets are not tractable. He believes that whatever angle the bullet has at the muzzle the bullet will retain throughout its flight. In otherwords, the longitudinal axis of the bullet remains fixed in space from muzzle to target; it doesn't nose over. I have been unable to obtain any source supporting this view from this particular person, however.
In contrast, I believe that a bullet that is just stable at the muzzle, i.e., not overspun or over-stabalized, will follow its trajectory like a well thrown football. However, other than a mathematical reference to tractability (see this web page), I can't find any source material supporting my belief either.
Does anyone have an informed view concerning this matter? The issue is of some import, especially for long range shooting, since it impacts directly upon the aerodynamic efficiency of the bullet. If a bullet's axis is fixed in space, one would expect higher drag as the bullet began to expose a greater area to the relative wind.