On the Applied Ballistics Facebook Page, there was a fascinating series of posts showing traces of bullets at various speeds from Mach 0.86 to Mach 3.0. At the slowest speed, Mach 0.86, i.e. 962 FPS, there is turbulence behind the bullet, but no clear shockwave. At the highest velocity, Mach 3.0 (3375 FPS at sea level, 68° F), there is a dramatic double nose and tail wave formation.
To learn more, visit TheScienceofAccuracy.com. On that site you’ll find exclusive video content and you can subscribe to member’s only Podcasts. And you can purchase Applied Ballistics books on the Science of Accuracy webstore.
Mach 3.00 Bullet Flight Image
At Mach 3 (3355 FPS) this bullet now has a strong and well established shock wave forming at the tip, and at the base. Unlike the transition through Mach 1.0, nothing really interesting happens to the aerodynamics or shock waves meaning the aerodynamics and stability are: continuous, easy to predict, and model. As you go faster, the shockwaves make a shallower angle because the bullet is moving forward 3X faster than the shock wave is moving away from it. So the shock wave makes an angle that has a rise/run ratio of 1/3.
If a bullet flew within 10 feet of you traveling this fast, it would be about as loud as a 22 magnum. You’d certainly want hearing protection as the energy contained in a Mach 3 shock wave is high! How high…? Well, in 10 yards, this bullet slows from 3355 FPS to 3334 FPS in a time of 0.0090 seconds. The 55 ft-lb of kinetic energy lost during this 10 yards is due to aerodynamic drag on the bullet, which is comprised of wave, base, and skin friction drag components with the majority of the drag being due to shock wave formation. Expending 55 ft-lb of energy in 0.0090 seconds requires a power output of 6111 ft-lb/sec = 11.1 horsepower, most of which goes into creating the shock wave. Remember it’s a 3-D cone that travels great distance, and it gets its energy by stealing velocity from your bullet!
Mach 1.00 Bullet Flight Image
Many shots were fired to capture an image of the transonic shockwave structure at exactly Mach 1.00. With the bullet now moving at the speed of sound, the local airflow on some parts of the bullet exceeds Mach 1.0. Anytime something is moving thru the air faster than the air can get out of the way, you get a compression wave, aka “shock wave”. That’s what’s visible in this image — the areas where the air density changes rapidly (in the compression wave) are visible as near vertical lines and a detached bow wave out front. As the bullet progresses through transonic speed, this shockwave structure develops which has strong effects on the drag (wind sensitivity) and stability of the bullet.
The exact development of the shockwaves and the resulting effects are unique and sensitive to the bullet geometry, and become very difficult to predict through the transition from subsonic (incompressible flow without shock waves) to supersonic (compressible flow with shock waves). Each bullet geometry does this differently which is why it’s difficult to determine transonic stability criteria for bullets of different shapes.
Mach 0.86 Bullet Flight Image
Here’s a bullet at Mach 0.86 (86% the speed of sound, which is 962 FPS at 61° F). As you can see, this 0.86 Mach is not fast enough to make any discernable waves but you can see turbulence in the bullet wake (right side in photo). The beginning of small shock waves can be seen on the bullet tip, and at the bearing surface/boat tail juncture. For the most part, all of the airflow around this bullet is subsonic. You wouldn’t hear a supersonic ‘crack’ from this bullet flying past the observer.
On the Applied Ballistics Facebook Page, there is a fascinating series of posts showing traces of bullets at various speeds from Mach 0.86 to Mach 3.0. At the slowest speed, Mach 0.86, i.e. 962 FPS, there is turbulence behind the bullet, but no clear shockwave. At the highest velocity, Mach 3.0 (3375 FPS at sea level, 68° F), there is a dramatic double nose and tail wave formation.
To learn more, visit TheScienceofAccuracy.com. On that site you’ll find exclusive video content and you can subscribe to member’s only Podcasts. And you can purchase Applied Ballistics books on the Science of Accuracy webstore.
Mach 3.00 Bullet Flight Image
At Mach 3 (3355 FPS) this bullet now has a strong and well established shock wave forming at the tip, and at the base. Unlike the transition through Mach 1.0, nothing really interesting happens to the aerodynamics or shock waves meaning the aerodynamics and stability are: continuous, easy to predict, and model. As you go faster, the shockwaves make a shallower angle because the bullet is moving forward 3X faster than the shock wave is moving away from it. So the shock wave makes an angle that has a rise/run ratio of 1/3.
If a bullet flew within 10 feet of you traveling this fast, it would be about as loud as a 22 magnum. You’d certainly want hearing protection as the energy contained in a Mach 3 shock wave is high! How high…? Well, in 10 yards, this bullet slows from 3355 FPS to 3334 FPS in a time of 0.0090 seconds. The 55 ft-lb of kinetic energy lost during this 10 yards is due to aerodynamic drag on the bullet, which is comprised of wave, base, and skin friction drag components with the majority of the drag being due to shock wave formation. Expending 55 ft-lb of energy in 0.0090 seconds requires a power output of 6111 ft-lb/sec = 11.1 horsepower, most of which goes into creating the shock wave. Remember it’s a 3-D cone that travels great distance, and it gets its energy by stealing velocity from your bullet!
Mach 1.00 Bullet Flight Image
Many shots were fired to capture an image of the transonic shockwave structure at exactly Mach 1.00. With the bullet now moving at the speed of sound, the local airflow on some parts of the bullet exceeds Mach 1.0. Anytime something is moving thru the air faster than the air can get out of the way, you get a compression wave, aka “shock wave”. That’s what’s visible in this image — the areas where the air density changes rapidly (in the compression wave) are visible as near vertical lines and a detached bow wave out front. As the bullet progresses through transonic speed, this shockwave structure develops which has strong effects on the drag (wind sensitivity) and stability of the bullet.
The exact development of the shockwaves and the resulting effects are unique and sensitive to the bullet geometry, and become very difficult to predict through the transition from subsonic (incompressible flow without shock waves) to supersonic (compressible flow with shock waves). Each bullet geometry does this differently which is why it’s difficult to determine transonic stability criteria for bullets of different shapes.
Mach 0.86 Bullet Flight Image
Here’s a bullet at Mach 0.86 (86% the speed of sound, which is 962 FPS at 61° F). As you can see, this 0.86 Mach is not fast enough to make any discernable waves but you can see turbulence in the bullet wake (right side in photo). The beginning of small shock waves can be seen on the bullet tip, and at the bearing surface/boat tail juncture. For the most part, all of the airflow around this bullet is subsonic. You wouldn’t hear a supersonic ‘crack’ from this bullet flying past the observer.
ELEY .22 LR ammunition has certainly been the choice of champions in high-level international smallbore competition. But ELEY is not resting on its laurels. ELEY’s engineers have worked hard to develop two new types of rimfire ammo — one fast (“force” high-velocity), one slow (“contact” subsonic). ELEY force and ELEY contact, the latest additions to ELEY’s product line, will be officially launched at SHOT Show in Las Vegas next week.
Black Casings — Not Just for Looks
Designed for power, ELEY force is a new, high-velocity .22LR round that delivers both superior energy AND accuracy. ELEY force features a new propellant with a distributed pressure curve. This provides more energy during the in-barrel “burn time”, accelerating the bullet to a high velocity. Force is optimized for semi-auto rimfire rifles.
The cartridge brass for ELEY force is matte black, the result of a patented oxidisation process, first used with Eley edge (introduced in 2013). ELEY force is now the second type of ammo with black cases, which are dark for a good reason. According to ELEY’s engineers: “The black oxidized case finish increases friction between the case and projectile. This regulates and controls the force required to release the bullet, stabilizing the projectile and increasing ballistic consistency and accuracy.”
ELEY Contact — The Subsonic Solution
ELEY contact is a subsonic semi-automatic .22LR round designed for extreme accuracy, reduced noise, and minimal recoil. The reduced recoil allows the shooter to recover his sight picture more quickly. This is especially important for rapid-fire shooting with semi-automatic rimfire rifles.
Both ELEY force and ELEY contact are engineered with a heavier 42 grain bullet for high energy and are coated in a specially-formulated paraffin wax to minimize build-up in actions and magazines.
ELEY’s History — A Success Story Spanning Two Centuries
A company with a rich heritage, ELEY has been making ammunition for 187 years. The company was first established in 1828 in London and was later moved to Birmingham, beginning a long and proud tradition. (Learn about ELEY’s history.) Over the years, ELEY has pioneered many technical innovations. ELEY now specializes in .22 LR caliber cartridges, and ELEY’s match ammo has a remarkable track record in competition. At the 2012 Olympics, 14 out of 18 smallbore shooting medals were won by shooters using ELEY ammunition.
ELEY Test Facilities in USA, UK, and Germany
ELEY tells us the “every current ISSF Smallbore World Champion uses ELEY Tenex ammo”. That success can be attributed (at least in part) to ELEY’s technical testing facilities in the UK, Germany, and the USA. At these test centers, competitive shooters can test ammo lots in their particular match rifle to ensure the best match of barrel and ammunition. To learn more about the ammunition testing facilities and ELEY products, visit www.Eley.co.uk.
AR this, AR that… sometimes it seems the gun world has gone AR crazy. There is even a book specifically dedicated to reloading for AR-platform rifles. This may seem superfluous when there are so many other reloading manuals on the market. However, there are some special factors to consider when reloading for ARs and other semi-automatic rifles. Cases should be full-length sized, with adequate shoulder bump and neck clearance (more than you might run with a bolt gun). Cartridge pressures must be appropriate for the AR platform, and you want to select powders that minimize fouling. Also, when loading for an AR you may want to experiment with cannelured bullets and crimping. And of course, rounds must be loaded to mag-length. Lastly, with the advent of the 300 AAC Blackout (and similar cartridges), many AR shooters now are experimenting with heavy 30-cal bullets in subsonic applications. AR owners will experience a “reloading learning curve” when moving from .223 Rem to the more exotic, subsonic 30-caliber cartridges.
These and other concerns are covered in Lyman’s new AR Reloading Handbook. This comprehensive reloading guide provides the AR shooter with reloading data for nearly all popular AR-platform chamberings. In addition to data for the standard .223 Rem, the following cartridges are also covered: 6.8 Rem, 300 AAC Blackout, 7.62×39, 450 Bushmaster, 50 Beowulf and others.
Lyman touts its new book: “Reloaders will appreciate the wealth of AR-specific reloading data [for] all popular brands of bullets and powders. Specialty cast bullet and sub-sonic data further expand the usefulness of the handbook. Interesting articles by well known and popular firearms journalists are also included. These cover such areas as ‘Reloading for Suppressors’ and ‘Cartridge Interchangeability”. Finally all this AR data is presented in a full size, easy-to-use 8 1/2″ x 11″ format.”
Sierra Bullets rolled out few new products for SHOT Show 2012. The one new bullet is a .30-caliber flat-based bullet, the 125gr OTM (open-tip match HP) MatchKing, item #2121. This unique flat-based bullet was designed in conjunction with AAC (Advanced Armament Corporation) and Remington for the new .300 AAC Blackout (BLK) cartridge, a relatively small cartridge based on the .223 Rem necked up to .30 caliber. The bullet length is tailored to correctly fit and feed from AR-15 platform magazines. The relatively light weight of Sierra’s new 125gr MK allows it to reach fairly impressive velocities even with a modest powder charge. Of course it can also be used in subsonic mode, running at sub-Mach velocities. However, it is more typical for .300 BLK shooters to run a heavier bullet, such as the 240gr SMK, for subsonic applications (the heavier projectile delivers much more downrange energy at subsonic MVs).
The projectile’s Open Tip is pinched for greater uniformity in the same manner as Sierra’s Palma Competition bullets. The G1 BC is surprisingly high for a relatively short, flat-based bullet: 0.310 (below 1600 fps), 0.330 (1,600-2,000 fps), 0.338 (2000 – 2650 fps), and 0.349 (above 2650 fps). Though it will perform well at low velocities in the .300 BLK, this bullet can handle the higher velocities produced by common .30 cal mid-sized cartridges, such as the .30-30.
The new 125gr Matchking is now being loaded in factory ammo, including Remington’s Premier Match, which retails for $34.00 for a 20rd box. These 125gr bullets are available now from MidwayUSA for $34.99 per hundred.
On the Applied Ballistics Facebook Page, there was a fascinating series of posts showing traces of bullets at various speeds from Mach 0.86 to Mach 3.0. At the slowest speed, Mach 0.86, i.e. 962 FPS, there is turbulence behind the bullet, but no clear shockwave. At the highest velocity, Mach 3.0 (3375 FPS at sea level, 68° F), there is a dramatic double nose and tail wave formation. 
