First round pop. Why?

[UnSafe]

Pretending I was a 50yd Bullseye Pistol shooter today, I could really hear the first round "Pop" with my new Sparrow suppressor on an ATI 1911/22.

So, what's the science behind it? The air pressure is the same inside, be it 2 sec or 2 minutes after the last shot. Heat, properties of lingering propellant gasses still inside, my failing hearing, noise fairies?

Fun to shoot and able to clean the paint off my 4" target.

Anyone 'splain sum fiziks to me?

 

[Okie4570]

Was your ammo subsonic?

 

[doctorjj]

The prevailing thought is that it's oxygen in the barrel and can that causes it. Once the first round uses up the extra oxygen, no more pop.

 

[Glocktogo]

There's more oxygen for the propellant gasses to consume on the first round. After that, the can fills with gas and subsequent shots can't burn powder as effectively inside.

The Sparrow is known for FRP. That's really the only drawback it has. To solve this without the mess of shooting full on wet, empty a nasal inhaler/mister and fill it with regular water. Insert the tip into the end of the can while holding it vertical and give it 2-4 squeezes. No mess, but your FRP will be gone!

Looks like Doc was answering while I was typing too much!

 

[Okie4570]

I didn't catch the "first round" part... you guys are too good