Tech Tuesday: Amazing Schlieren imaging of Bullets in Flight

Every Tuesday, Applied Ballistics’ Facebook Page posts an interesting technical feature. Today’s “Tech Tuesday” (4/23/24) featured a fascinating video showing a bullet in motion. This Schlieren video shows a 6mm Berger LRHT Bullet traveling at 3163 FPS. The video shows the shockwave of the bullet and its turbulent wake. Schlieren Imaging: What it Shows Schlieren Imaging allows airflow features to be visible. You can clearly see the shock (compression) wave at front of the bullet. This bullet is moving at Mach 2.5, which is 2.5 times the speed sound. A compression wave is created when the air must move faster to get out of its way. This shock wave is what you hear when bullets pass you, if/when they are downrange. The energy required to compress the air into a’shockwave’ comes from the forward velocity of the bullet. This energy is then converted into heat and sound as the shockwave forms and dissipates. The turbulent wake around the base of bullet shows how/where base drag is applied. Skin friction drag is the third and smallest drag component for a bullet traveling at supersonic speeds. It is a viscous layer boundary effect and is not visible in this picture. Above is another Schlieren imaging video. This is a 6mm 109gr Berger LRHT at 2800 fps fired from a PRS Rifle at the Applied Ballistics Lab. Bryan Litz observes: “You can see the shock (compression) wave at front of the bullet.” A compression wave occurs when air must move faster than sound to clear the bullet. This is the case with this bullet, which is moving at Mach 2.5. Science of Accuracy Exclusive content for Subscribers Applied Ballistics offers a vast archive of ballistics-related technical information and exclusive videos. Subscribe to the Science of Accuracy Academy and get access to all this information, plus exclusive podcasts for members. Visit the Applied Ballistics Science of Accuracy Academy to learn more.