“Another way that stability is believed to affect bullet flight is the idea of over stabilization. The theory goes:

“A bullet that is spun excessively fast will not trace with the flight path. As a result, when the bullet drops on the downrange leg of the trajectory, it will retain a nose high orientation, which presents more surface area to the oncoming air flow, and causes increased drag, thereby reducing the effective BC.

“Although there is some truth to this statement, the increase in drag is commonly believed to be much greater than it actually is. It’s true that higher stability levels do produce a more rigid spin axis that tends to resist bending as the bullet follows its curved trajectory. However, even bullets with very high stability factors will still trace (sometimes called track) very well with the trajectory, the angle will only lag a little more than a slower spinning bullet. An exception to this statement is for very high angles of fire, near 90 degrees, where the bullet would have to turn its axis abruptly at the apex of the trajectory. Failing to trace is a consideration for artillery shells fired at high angles because if the round doesn’t trace, it won\u2019t hit the ground point first which is required to activate the fuse and detonate the charge. Bear in mind that even for such high angles of fire, failure to trace is still uncommon. For the small angles of even the longest range small arms trajectories, it is very easy for the axis of the bullet to trace with the trajectory….”

Case closed.

I have also recently received a U.S. patent for a new monolithic copper Ultra-Low-Drag rifle bullet design. Dan Warner made a first production run of these bullets just before Christmas. David Tubb just test-fired them for BC measurement over his 995.7-yard range instrumented with an Oehler System 88 Chronograph/Acoustic Sensor set-up. These 225-grain 338-caliber bullets measured 0.794 for BC(G1) at 65 degrees F. Average MV was 3378 fps and time-of-flight was 1.068 msec. The average airspeed over the 995.7-yards was 2766 fps (Mach 2.463), allowing for the 30.8 fps tailwind. He used a 35-inch Schneider barrel with a 7.5-inch twist rate. McDRAG estimated a BC(G1) of just 0.703 for this Mach 2.5 airspeed. The extra 12.9 percent drag reduction is attributable to “over-stabilizing” these bullets with an initial Sg of 2.75 (McGYRO and Miller). The coning angle was absolute minimum, and the bullets were flying essentially straight nose forward. There was no yaw-drag over 1,000 yards. McDRAG estimates are calculated to replicate outdoor test firing results for initial Sg=1.5 and about 2 to 5 degree average coning angles. The Oehler system calculated target impact speed at 2340 fps (Mach 2.1). David did not report any “nose-high” bullet impact prints. He did mention firing a 5-inch 5-shot group in early load development.

At 2,000 yards these bullets would be transonic and possibly be flying “nose high” at impact with a significant “Pitch-of-Repose” attitude angle.
I am going to try a 6.6-inch twist (20 calibers) 338 barrel on my 338 Lapua Magnum test rifle.

EDITOR: The illustration used in the original article is NOT from Applied Ballistics. As noted, this is a diagram from the University of Utah Health Sciences Library Firearm Ballistics Tutorial. It is deliberately very basic and is designed to illustrate in very gross terms, basic terminology such as yaw.