Bullets In Motion
High-Speed Photographs Are A New Tool
In Understanding Bullet Performance.
One of the early mysteries of bullets was how they acted in motion, because even when only propelled to black powder velocities, they usually couldn’t be seen by the human eye. Their path could be tracked to certain degree by what they hit (the reason for paper targets), and their terminal effects on various targets could be examined.
However, all this was static evidence, not the actual flight of bullets, either in flight or as they struck something. This led to some interesting conjectures. One early theory of trajectory suggested bullets flew absolutely flat for a certain distance, then dropped rapidly.
Even the invention of high-speed photography didn’t solve all the mysteries. For decades it was “common knowledge” that the lead tips of softnose spitzers melted off during flight due to heat developed by air friction, because early photographs of bullets in flight showed a much blunter nose. But this was caused by technical problems with the photography, and was disproven both by trajectory data and better photography, especially movie film. Yet we still hear this “fact” repeated today, proving once again it’s harder to dispel a myth than start one. (As Charlie Hasbrouck, the newspaper reporter in The Man Who Shot Liberty Valance, so cynically noted: “When the legend becomes fact, print the legend.”)
The standard speed of 35mm motion picture film used in theaters is 24 frames-per-second, but that’s an economical compromise between the frame speed required to impart smooth motion to the human eye and the cost of film. Specialized film cameras eventually increased the rate to thousands of frames per second, but the cameras and the vast amounts of film required increased expenses enormously.
Digital photography changed the game, allowing tens of thousands of frames per second at much less expense. While the equipment is still expensive, the cost of film and development is eliminated. Along with transparent bullet-test media, digital photography literally opened our eyes to what was actually going on. One of the first long-time theories to be disproven was the guess that plastic-tipped bullets opened up due to the tip acting like a log-splitting wedge. This notion first appeared with the metal-tipped bullets like the Remington Bronze point, but high-speed digital photography showed the plastic tip normally drifted away from the bullet after impact. The quick expansion was caused not by the tip, but by the relatively large cavity under the tip.
One of the specialists in super-speed digital imaging is Nathan Boor of Aimed Research in northeast Ohio. The website claims, “Our 500 nano-second photography, equivalent to 1/2,000,000th of a second exposure, using DSLR cameras provides greater resolution and depth of field over any high-speed professional video camera. Aimed Research can acquire multiple camera angles at the exact same moment for time-slicing or bullet time perspectives. Strobe-lit photographs can be acquired showing a projectile at two points along its trajectory in the same picture for yaw and rotation measurements.” Not to mention expansion and other characteristics.
Among the interesting images is one of the new Cutting Edge Raptor hunting bullets as it expands in clear ballistic gel. The Raptor is a monolithic bullet made of copper or brass with no lead core, but the “petals” are designed to break off, unlike those in many other hunting monolithic bullets. This isn’t a totally new idea—both the South African GS Custom HV and Norma Kalahari are also designed to lose their petals—but to my knowledge the Raptor’s the only one made in America, and also the only company that makes a handgun version.
My wife Eileen and I used Raptors this past hunting season after shooting some into a couple of kinds of media. They tend to shoot very accurately and work very well on game, but the high-speed sequence images taken by Aimed Research clearly show the exact and consistent way they work. You can take a look on Cutting Edge’s website. Thanks to advances in photography, handloaders no longer have to speculate on how bullets work either in the air or when they stop.
By John Barsness
Cutting Edge Bullets Safari Raptor
This particular bullet is a Cutting Edge Safari Raptor in .375 caliber, weighing 275 grains.
Note as it enters the gel the petals at the front of the nose break off and become
secondary missiles. The back of the bullet then drives on like a solid.
Aimed Research, Youngstown, Ohio
Cutting Edge Bullets, LLC
75 Basin Run Road,
Drifting, PA 16834
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Four of John Barsness’s nine books are on firearms and shooting. His latest, Rifle Trouble-Shooting and Handloading, was published in 2012 by Deep Creek Press, and is available through www.riflesandrecipes.com, or by calling (406) 521-0273.
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