Subsonic ammunition has been in high demand in recent years. The casual shooter may wonder what that’s all about. We’ll cover that in this article.
For our purposes, subsonic is a term that relates to the speed of a bullet traveling through the air, measured at the muzzle, at less than the speed of sound. A sound wave travels through the air at 1,125 feet per second. That’s the speed of sound. Bullets traveling less than 1,125 ft/s are considered subsonic. Bullets traveling faster than the speed of sound are considered supersonic. But why does that matter?
You’ve probably heard of the term sonic boom. A sonic boom is a sound associated with shock waves created when an object travels through the air faster than the speed of sound. The power, or volume, of the shock wave depends on the size and shape of the object. An airplane makes a very loud sonic boom in comparison to a bullet. Nonetheless, a bullet traveling at supersonic speed makes a boom that can be quite loud to the human ear.
Why does any of this matter? Suppressors, that’s why. Suppressors (a.k.a. silencers) are extremely popular. Reducing the sound of a gunshot makes the shooting experience more pleasurable for the shooter, bystanders, and neighbors. It’s also safer for everyone’s ears. But firing guns with suppressors can still be extremely loud. That’s because the silencer does nothing to suppress the sound of a supersonic bullet’s sonic boom.
Enter subsonic ammunition. Since it’s traveling at < 1,125 ft/s, there is no sonic boom. The silencer suppresses the muzzle blast, you know that little explosion in the gun’s chamber, and a much quieter shooting experience is the result.
A sidenote on suppressors, they are not as difficult to purchase as one might imagine. They are legal in 42 states at the time of this writing. There are several online dealers that will handle your paperwork and ATF approval. You can have your suppressor in about 90 days.
Like most anything, there are pros and cons to subsonic ammunition. We’ve already hit on the pros, using subsonic ammunition with a suppressor is better for everyone’s ears.
The cons, supersonic ammo has a higher velocity, better range, more stopping power, and a flatter trajectory than subsonic ammo. Go with supersonic for long range shooting, hunting, and self-defense purposes.
Magtech’s 200-grain 300 Blackout ammunition is a great example of a rifle round that’s easy to suppress. It leaves the barrel at around 1,000 ft/s. It’s about as close to “Hollywood quiet” as you can get.
Pistols and pistol caliber carbines are also popular with suppressor owners. Magtech offers two subsonic 9mm Luger rounds, a 147-grain full metal jacket and a 147-grain jacketed hollow point.
Also on the pistol side, note the velocity of standard 230-grain 45 Auto ammunition. Standard 45 Auto like Magtech’s 45A has a muzzle velocity of about 840 ft/s. It won’t be labeled as subsonic since it’s not a special load. Just know that it’s traveling at less than the speed of sound making it a great suppressor option.
Now you know the deal on subsonic ammunition and suppressors. Give it a try the next time you hit the range. See if it’s as quiet as Hollywood would have you believe.
