Supersonic is a description of the speed of a bullet once it is fired, specifically speeds above 1,126 feet per second.
This is the speed of sound, so anything traveling faster will break the sound barrier and create a sonic boom.
Small arms do not create the sonic boom that a jet fighter would, but there is still a very loud and distinct “crack” as the bullet moves through the air at high speed.
Supersonic ammunition is common and is usually not marketed as supersonic as many calibers and ammo types move this quickly of even faster by default.
Here's an overview of supersonic ammunition and its implications:
Velocity and the Sound Barrier
The speed of sound in dry air at sea level at 20°C (68°F) is roughly 1,125 feet per second (FPS). Supersonic ammunition has a bullet velocity that surpasses this benchmark.
When a bullet travels faster than the speed of sound, it produces a distinct "sonic crack" or "sonic boom" as it breaks the sound barrier.
Most standard ammunition for rifles and many handgun calibers are inherently supersonic due to their typical performance requirements.
Range and Accuracy
Supersonic ammo usually offers flatter trajectories over longer distances, making it preferable for many shooting applications, including hunting and target shooting.
Defensive and Military
The increased velocity generally results in higher kinetic energy, making supersonic rounds more effective for stopping threats or achieving specific tactical objectives.
Ballistics and Performance
Supersonic rounds typically have a flatter trajectory compared to subsonic rounds, making them more predictable and easier to aim over varying distances.
The higher velocity of supersonic ammunition translates to increased kinetic energy, which can result in greater impact force and terminal ballistics.
Supersonic rounds come in a variety of bullet designs, from hollow points for self-defense to full metal jackets for target shooting.
Calibers and Availability
Most rifle calibers, like .223 Remington, .308 Winchester, and 7.62x39mm, are naturally supersonic under standard conditions. Many popular handgun calibers, such as 9mm and .40 S&W, also typically fall into the supersonic category with standard loads.
While subsonic ammunition requires specific design considerations to keep velocities down, most traditional ammunition is inherently supersonic.
Supersonic rounds are generally louder than subsonic rounds due to the additional sonic crack. When using suppressors, this sonic crack remains, whereas the noise from the gunpowder ignition is reduced.
Higher velocities can result in increased wear and tear on a firearm's barrel over time, especially with specific high-velocity rounds.
In summary, supersonic ammo is the standard in many shooting applications, characterized by bullet velocities that exceed the speed of sound.
Its inherent properties provide a balance of range, accuracy, and kinetic energy, making it suitable for a wide array of shooting sports and defense situations.