Suppressors 101 – A brief introduction: So over the past couple of weeks I have seen several videos with people shooting suppressors and complaining about how loud their guns sound and how they expected a suppressed firearm to be much quieter. So lets begin suppressors 101 and break it down, “Barney Style”:
There are 3 factors that dictate noise on a firearm. While each firearm has its own unique characteristics that cause sound, there are 2 that factors that remain constant in every application.
- The physical explosion of the projectile coming exiting the barrel
- The speed of the bullet and the supersonic crack
- The sound of the action/bolt
Lets start with the physical explosion. The suppressor will do its job in suppressing the explosion as the projectile leaves the barrel, thus controlling the first source of sound. The extent of the suppression can be better or worse depending on the brand or caliber size you choose to utilize on your weapon system. Caliber specific suppressors vs. Multi-caliber suppressors can effect the decibel level of that first explosion differently based on the size and baffle pattern.
Next is the supersonic crack of the projectile. It should be noted that suppressors will actually increase the FPS of your projectile causing it to be faster and potentially louder depending on grain weight. If you use a suppressor and shoot standard high velocity ball ammo you are effectively rendering your can useless as the supersonic crack is typically the most audible sound people hear. Some folks will port barrels, use short barrels and utilize flash cans which can produce an extremely loud bang (louder then the supersonic crack) from the firearm, however those people typically like making big LOUD sounds to ensure everyone else knows they have an IMPORTANT gun and suppressors aren’t for them.
The key to controlling the supersonic crack is the combination of the right ammunition/grain weight, temperature and elevation. Example; shooting a 115 grain .9mm bullet out of any suppressor at any temperature or elevation is going to be loud because the bullet is traveling anywhere between 1150 FPS and 1500 FPS. That range of speed is supersonic and will cause a loud crack. (Sound Barrier is typically right around 1,087 FPS to 1,100 FPS depending on elevation and temperature) If you use a 147 grain .9 mm bullet which sits between 950 FPS and as fast as 1450 FPS with +P ammo you are more often then not, sitting at or below the sound barrier and removing the audible crack. While the bullet is now quieter, this is not without its drawbacks, as the bullet is now transonic and at range/distance can start to do strange things (like wobbling) in flight. This is where you need to decide the purpose and application of your weapons system and environment in which you plan on using it. Subsonic pistol ammo, .300 black out, 5.56 or 7.62×39 ammo is probably not the best choice for targets outside 150 yards. Subsonic .308 ammo is probably best utilized within 200 yards. Some people like to talk about kinetic energy on target….if you are inside the ranges/distances above….last time I checked a projectile traveling at even 800 FPS is still going to put a hole in you. If that first bullet doesn’t stop the threat…then turn the target into a pin cushion. At the end of the day, shot placement is more important then just relying on bullet deformation and frangibility to make up for crappy aim…..but I digress..***steps down off soap box***
The last source of sound would be the functionality of the specific firearm you are shooting. AR style rifles use a gas or piston system to eject the spent cartridge and load the next round. This makes an obviously audible sound. A typical pistol would have a blow back action, where the bolt is reciprocationg using the force of the explosion inside the chamber instead of using the gas propellant or a piston to move the bolt and eject and reload. The use of a bolt action rifle would have zero sound as it is locked in place and requires manual ejection and reloading, which can be done very quietly and slowly. At this point you are hearing the firing pin as there is no movement in the chamber other then the firing pin striking the primer.
So what did we learn? Key things to remember:
- Effectiveness of the suppressor for your specific weapons system
- Ammunition – Caliber, Grain weight and muzzle velocity
- Weapons platform and situational application,
Shooting suppressed in my opinion is the only way to go if you live on the range like I do. It is great indoors, in a shoot house, its better for your ears and most importantly it is also more enjoyable for those all around you. Don’t be that giant fireball explosion from the end of your gun guy……Nobody likes you.
Article by, Andrew Eager