- What blowback is
- How different weapons are impacted
- How to prevent it from causing problems
What is Blowback?In order to illustrate the concept, let's look at an extremely common semi-automatic weapon: the AR15. When you pull the trigger on your AR15, you'll set in motion a series of events - which can be simplified into these steps:
- The powder is ignited - which creates the pressure required to send the bullet down the barrel (with gas expanding behind it)
- Once the bullet passes the gas block (which is typically under the front sight post or rail), some of the gas is redirected back through the gas tube and into the chamber
- The gas pressure entering the chamber allows the bolt to unlock and cycle - which loads the next round into the chamber
How are different weapons impacted?At this point, let's move away from the AR15 example and start focusing on different styles of weapons: Single Shot Weapons (such as bolt action, lever action, break open, etc...) Weapons that are cycled manually aren't impacted by blowback at all. In those cases, adding a suppressor won't have any negative effects - and you'll benefit from reduced sound, increased accuracy & range, and reduced recoil. Gas Blowback Weapons The AR15 we already talked about is a common example of a gas blowback weapon - but there are many others. In this case, the additional blowback can cause several issues:
- The faster bolt speed will cause the carrier & bolt parts to wear out faster - although this typically isn't noticeable for most users.
- Since the bolt is cycling faster, it's possible to actually outrun the spring in your magazine. (This is often referred to as Bolt-Over-Base.) In this case, your weapon will either jam or lock up on an empty chamber.
- The weapon will get dirtier faster since there is more gas in the chamber.
- You'll generally smell more gas; and, depending on the weapon, may feel it blowing into your face & eyes as you shoot.
How can you prevent too much Blowback?Although we're going to focus on the AR15/10 style weapons here - these same concepts will apply to pretty much any gas-operated firearm. Before going any further, if you're not having negative issues - don't try to solve a problem that doesn't exist. If you're having one or more of the issues described above, try these simple suggestions:
- Use a heavier buffer - This will slow your bolt back down and will solve most cycling problems for just a couple of bucks
- Try a Gas Buster or Griffin SN-ACH charging handle - If you want to reduce the amount of gas escaping around the charging handle, then this is a great accessory!