The PopStop – An Innovative Solution to a More Silent Suppressor

Discreet Ballistic’s PopStop is a proprietary device that eliminates what is commonly known as first round pop in suppressors. First round pop occurs when oxygen contained in a “cold” suppressor meets unburnt hot propellant. With certain suppressors, first round pop can account for more than twice the impulse noise as the subsequent shot through the same suppressor.

We sat down with the inventor, David Stark from Discreet Ballistics to talk a bit more about this device.

Q:  So, can you explain the idea behind this device?

A:  The original concept was many times people only take one shot, whether they are hunting out of their bathroom window, or they are hunting in the woods.  With first round pop, you are looking at up to 8 decibels louder than other shots, so let’s make your first shot as quiet as subsequent shots. 

Christmas morning, my dad and I were a bit hung over from the last night’s festivities.  He is an MIT engineer, I am not.  I mentioned, “Hey dad, here’s a problem with suppressors called ‘first round pop’, due to atmosphere existing in the suppressor and the consequent burning of the oxygen by the hot powder with the first round.  Subsequent rounds are quiet because all of that oxygen has been burned out.”

I asked, “how do I get rid of this?” 

We went back and forth, and we came up with the concept of purging the atmosphere with an inert gas.  And what better inert gas than CO2?  It is both heavier the atmosphere, so it will stay in the can, and it is plentiful and easily accessible since we have cartridges that are used in pellet guns and so on.

As far as delivery method, I used to mountain bike race.  So, we had these CO2 inflators for tires when you changed out the tubes.  It was an off-the-shelf delivery method for it. 

Q:  This reminds me of guys putting water in their cans… 

A:  Yeah, what people were doing before, they were spitting in their cans, pouring water into their cans, blowing cigarette smoke into the can, literally with a round chambered, blowing cigarette smoke…just really stupid things.

And, what we have also found, with the help of a former Army Special Forces sniper, is that not only do you eliminate first round pop, but because you make the atmosphere in the suppressor consistent, you increase the consistency of velocity. 

And indeed, it does significantly improve standard deviation consistencies with velocity.   That is almost more significant than the reduction of sound because the whole goal of precision shooting is to keep your bullets going at a consistent velocity as possible. 

Finally, another benefit is it reduces flash.  Along with first round pop, you have first round flash, which is the result of that oxygen burning.  You’ll see this if you ever shoot at night.  This can be important for snipers who are trying to avoid detection.

Q:  You mentioned another unique feature that might make some in Law Enforcement take notice.

A:  This is kind of crazy, but someone suggested that I contact some police departments who deal with meth house problems, because you have SWAT teams that go into these houses with chemicals lingering in the air, and they have these short barrels AR-15s with suppressors, they are seeing explosions because of this flash coming out of their silencers, and people can be burned as a result.

Again, this is an unconventional thing, it’s not for everybody, but as suppressors become more popular, people are going to want quieter.  In the same way people want the fastest car, and they will use gadgets like the PopStop to achieve that. 

That said, I’m in no way trying to talk myself up, and perhaps this is a product that is ahead it its time.  Surely, when it comes to suppressors, there are more advancements coming down the line, and perhaps what my dad and I developed is just simply some part of that.