Suppressor gases

[Resq47]

Don't forget about the lead styphnate in primers. Lead free primers are part of the non-toxic ammo recipes.

[blkexp98]

How do the piston uppers affect the amount of smoke and ammonia smell? I know some gas is coming via the chamber after looking at my brass after shooting suppressed. Its just a matter of how much compared to the gas tube. Guess it still vents though just further up with a piston upper.

If you want to try buffers you may could try a David Tubb carrier weight in combination with a heavy buffer. That way you could tweak the weight a little easier. I bought a H3 buffer from "Heavy Buffers" and he will sell the individual weights as well. He had steel, tungston and lead last time i checked and if yuou knew the weight you wanted he can custom make it as well. The e-mail is heavybuffers(at)gmail(dot)com. My 16inch midlength upper functions fine suppressed and non suppressed with the heaviest tubb carrier weight the h3 buffer and a tubb flatwire spring. That may or may not work for you as we all kniow all rifles dont act the same. Also remember if your using a carbine stock and have a fixed stock buffer you can cannabalize the weights to make a different weight buffer.

Im glad i found your topic as i was really considering SBRing my lower and building a 10.5 upper to shoot primarily suppressed.

[CarlosDJackal]

The piston upper actually reduced the amount of blow back. I don't worry about gases hitting me in the face as it did when I was using a DI system on this.

What really affects the gas blow back is the suppressor. If you look at the video, you're see that the gases are coming out of the ejection port.

I have been shooting the SBR without the suppressor lately and I prefer it that way. theonly issue is that it does require some good hearing protection (IE: Surefire EarPro Defender Plus).

[SuicideHz]

There IS ammonia in the spent gases. This is what causes the ammonia smell and this is what causes the ammo to be non-corrosive.

Corrosive ammo does not have the ammonia smell and many people use windex containing ammonia to neutralize the salts that are corrosive.

I guess if you make the powder with chemicals that will produce ammonia when burned, that will neutralize any problems...

Piston uppers keep the higher pressures out of the bolt and carrier and it is those which force those gasses out of the cracks around the charging handle.

Also, gas from the gas tube travels down the key and pushes the bolt forward and carrier rearward. Excess gas vents through the holes in the side of your carrier and you usually get some of that back in your face too.

A pistol eliminates most of that gas.

[Robb Jensen]

I'm finding that I get more gas out of the upper and ejection port with my 16" Colt 6920 upper with the PWS piston kit on it with my M4-2000 Mod 1 mounted and it on the suppressor setting. More gas than if the can wasn't mounted and it's on the regular setting. I'm finding that the suppressor setting really only makes the rifle operate close to the same bolt velocity as it normally does unsuppressed and makes recoil stay the same.

With my direct inpingment 10" SBR unsuppressed vs. suppressed, the felt recoil to the shoulder increases as does the amount of gas coming out of the upper/ejection port while running the suppressor. The muzzles lifts less with the cam mounted (acts as a comp, I think mostly because of it's weight for muzzle lift and it makes the recoil more linear).

[SuicideHz]

Well darn. The reason I was looking to get the PWS piston was to help control some extra gases and fouling. I guess I can save the $400 and just invest in a gas buster?

[blkexp98]

That makes two of us. Even with my heavy weights i still get a decent amount of blowback so i dont think timing the bolt is possable either.

My current setup though i havent had a high round count with it between cleanings is:

H3 buffer: 5.4 oz
Tubb carrier weight with carbide insert: 4.05 oz.
Tubb flatwire spring: Says 22% extra power vs standard spring and 10% vs their round CS spring.

With that said my shooting buddy feels my rifle actually has more recoil with the weights. Since i havent had that high of a round count between cleanings i wouldnt call it reliable yet. I have also tried the high temp silicon on the charging handle with no real big change. Then again it could have been this ejection port issue we are discussing causing the sensation it wasnt working.

Other than careful handloading and testing powders and primers i cant think of a good way to reduce the smoke.

[Gentle Ben]

A friend of mie has the Phantom and it gasses him quite a bit as well.

My 10.5 LMT and M4-2K combo gassed me a fair amount even with the gas buster c/h, but then I did the silicone RTV mod to it and that made it alot more pleasant when shooting from my right shoulder; when shooting around barricades from my left shoulder, I got all the gas from the ejection port in my face.