Subsonic Ammo: When and Why You Should Use It

Shooting quieter – an appealing thought whether you’re in the field hunting or at a crowded range. Suppressors are one way to help tame the sound of your favorite firearm, but another option to try is using subsonic ammo. What is subsonic ammo? We’ll answer that question, and when you should use this ammo, in this guide! 

What is Subsonic Ammunition 

Put plainly, subsonic ammo is ammunition where the bullet is travelling less than the speed of sound. The supersonic crack that you hear when shooting is created when a bullet is travelling faster than the speed of sound, which is around 1100 feet per second (FPS). When you look at a box of subsonic ammo, you will often see listed velocities around 1,050 FPS or lower. This lower velocity ammo doesn’t carry the signature crack of a shot with standard ammunition, making the shot quieter. 

How does subsonic ammo achieve lower velocities? There are a couple of different ways. First, subsonic ammo often uses heavier projectiles when compared to standard velocity ammunition. A good cartridge example is 300 Blackout. Many subsonic 300 Blackout loadings feature bullets with grain weights in the 200 – 220 grain weight range. For a standard velocity loading, 300 Blackout will often feature bullet grain weights anywhere from 125 – 150 grains. The heavier projectile travels slower through the air, reducing its velocity and bringing its noise level down. 

Subsonic ammo may also be loaded with less powder than a standard velocity loading. A smaller powder charge means less propellent in the cartridge, which translates to lower velocities when the bullet leaves the barrel. Both techniques can be used, and often are combined, to help make ammo that is quieter. 

Practical Uses for Subsonic Ammunition 

Subsonic ammunition may not be for everyone, but it has some uses where it can be a great benefit. Let’s examine a few different cases where you may want to try it out. 

Range Shooting 

If you’re shooting on your property with neighbors relatively close by, or heading to a crowded public range, subsonic ammo can help cut down on the noise. It’s also a great addition if you’re shooting a suppressed rifle or handgun! A suppressed firearm using subsonic ammo can be incredibly quiet, making range day more fun for kids and new shooters who may be intimidated by the louder retort of an unsuppressed rifle with standard velocity ammunition. 

Hunting 

In some cases, using subsonic ammo can be a great benefit when hunting. When paired with a suppressor, it helps create an incredibly quiet shot that won’t spook game from the area and can give you better opportunities for a follow up shot. However, the limited effective range of subsonic ammunition means you need to be mindful of distance and keep your shots in ethical ranges, often only out to 100 – 200 yards at the most.  

If you choose to hunt big game with subsonic ammunition, also make sure to check your state regulations beforehand. Some states require an expanding type bullet (hollow point, ballistic tip, soft point, etc.) when hunting big game, so make sure your subsonic ammo uses one of these types of bullets. States may also require that ammunition meets a certain energy threshold to be legal to use, so check your ammunition box to ensure your ammo meets the legal requirements for use before hunting with it.  

Subsonic ammunition may have the best use in small game hunting. Subsonic options for 22 LR rifles and handguns are widely available, and when paired with a suppressor it is incredibly quiet. Small game hunts often take place at very close distances, so the ammo still offers enough terminal performance to be effective while also being quiet and fun for young or new hunters. 

Competitive Shooting 

Some shooters in competitions like 3-gun, IPSC, and USPSA may choose to use subsonic ammo. This is often because of its lower recoil impulse due to a smaller powder charge. Less recoil can help improve shooting times, making subsonics an appealing option to some. Shooting at these competitions is often done at shorter ranges, helping to nullify some of the drawbacks of steeper bullet drop at longer range. 

If you want to use subsonic ammunition for competition shooting, make sure you check the rules of your circuit beforehand. Some shooting circuits have minimum power ratings for ammunition, so make sure your ammo of choice meets these standards. Subsonics may not perform optimally in all semi-auto firearms as well, so check your firearms to ensure it runs well before competing.  

Impacts of Subsonic Ammunition 

While subsonic ammunition has lots of benefits, like lower recoil and less noise, there are a few drawbacks to keep in mind. 

• Limited range: Subsonic ammo has slower muzzle velocities due to heavier bullets and smaller powder charges. These slower bullets will drop off faster at longer ranges, making them less effective for long distance shooting. To use this ammo effectively, you will want to keep your shots within fairly close distances, especially if you plan to use it for hunting. If you want to switch between higher velocity ammo and lower velocity subsonic rounds, you will also need to re-zero your rifle to account for the point of impact shift. 
• Cycling: Some semi-auto firearms may have issues cycling subsonic ammo due to less available gas in the system to cycle the action. While some rifles like AR pattern and other modern sporting rifles have adjustable gas systems, not all semi-auto firearms do. Check to make sure that these rounds will work in your firearm before relying on them. 
• Limited choices: Your selection of subsonic ammunition can be limited depending on the cartridge you’re using. For small and intermediate cartridges, like 300 Blackout and 9mm, there are several widely available loadings. Larger hunting cartridges often won’t feature subsonic loadings, since it is difficult to make these cartridges perform effectively at lower velocities.  

While it’s not for everyone, subsonic ammunition can be a great choice for those looking to make shooting more enjoyable for first time hunters and shooters. If you want to be stealthier in the field or have a fun time on the range, this ammo can be a great choice to help make that a reality. So, give subsonics a try sometime, and pair it up with a suppressor for even more fun on the range and stealth in the field!