Loud ejection port noise

[BurtG]

Running a Seekins sp10 with a proof 20” 6.5cm barrel. Adj gas block.

using a 338 ultra or ultra 9 can.

Ejection port noise is super loud.

Would changing buffers or springs or ? Help this ?

Thanks.

 

[Obi-WanKannoli]

Nope, that is 'port pop'. Some combinations are louder than others but it's present on all gas operated AR's to some extent. You may (?) be able to reduce it with some buffer, spring, and AGB tuning but it's not going away.

 

[BurtG]

Nope, that is 'port pop'. Some combinations are louder than others but it's present on all gas operated AR's to some extent. You may (?) be able to reduce it with some buffer, spring, and AGB tuning but it's not going away.

I have a pile up of 16-20” 556s running OpsInc 12 th model , m496d , tbac cans etc and they are relatively quiet. Same for a Pof 308 20” piston with a Gemtech Sandstorm.

This 6.5cm is atrocious there’s got to be something to help
It

 

[Obi-WanKannoli]

I have a pile up of 16-20” 556s running OpsInc 12 th model , m496d , tbac cans etc and they are relatively quiet. Same for a Pof 308 20” piston with a Gemtech Sandstorm.

This 6.5cm is atrocious there’s got to be something to help
It

So on your 5.56 maybe those combos are just working better. For your 308, you really shouldn't hear any port pop since the physical piston is driving the bcg not gas (directly).
Again for your 6.5 I don't think there is much to do aside from playing with buffer springs and weights and reducing gas at your AGB.

 

[Obi-WanKannoli]

Port noise also comes from gas escaping out of the chamber and ejection port. Hence port noise on blow back PCCs and pistols.

Completely true, but it should be minimal compared to a gas gun.

 

[roostercogburn98]

Springs aren’t the answer, those are generally for addressing feeding/extraction issues. Look at heavier buffers or adjusting the gas. You need to slow your dwell time down to reduce port pop. Depending on the gas length and how much barrel is left after the gas tube, you might have some issues taking the port pop with that rifle. Try a different suppressor and see how that impacts your dwell time as well

 

[db2000]

I have an .308 SP10 18” Proof CF and SiCo Omega or 36M can I run on it. I have a Superlative Arms AGB I run on the “bleed off” setting. Frankly, I haven’t messed with the AGB looking to see if one setting over the other makes a difference on port pop but as is I don’t notice it overly aggressive or loud.
Fwiw I use a Tubbs flat spring, rifle buffer tube and KAK 5.6oz AR10 buffer.

 

[Skunk]

Most dudes blame port pop on the dog.

 

[Clayman]

Completely true, but it should be minimal compared to a gas gun.

No, the vast majority comes down the barrel. In fact very short dwell length tuned AR's run cleaner than many pistons suppressed because most pistons have a long dwell length and the bolt unlocks earlier.

 

[Clayman]

I would try running different suppressors. Long suppressors like that generally have pretty high back pressure. You can tune some of the gas and port pop out but you cannot overcome it. So while I'm sure you could improve it a bit I'd bet it's going to stay louder at ear with those vs shorter/higher flow rate offerings.