Sig P556 SBR

[Driller]

I put a folding stock on my Sig P556 after I got my stamp from ATF. I have heard of the cycling issues with sub sonic ammo. I was wondering if anyone has tried turning the adjustable gas valve over to allow for more gas pressure to blow back against the piston? I will be getting my .223 sub sonic ammo in this week. I will let you know how it turns out. Reading the manual it seems like it might work of course it does not talk about sub sonic ammo......Oh I also have the stamp for my .223 can.

 

[Mic]

Sweet!

 

[Texas1911]

Sub-sonic .223 is just a fancy version of .22 LR ... and has about the same gas pressure.

 

[ChunkyMonkey]

okay, you CAN NOT make such a thread without posting pics....talk about a let down teaser, lol....

 

[Driller]

Sorry, should have been thinking. That silver thing with the hole in it right above where the suppressor starts is the adjustable gas valve.

 

[Driller]

The adjustable valve was designed for heavy use and if the weapon became dirty and ejection issues started happening you could open the gas port more to allow more exhaust gas to push more pressure on the piston until you get a chance to clean the weapon. Not a good thing to do all the time with a clean weapon and super sonic ammo because of the increase in fatigue and wear. But with sub sonic ammo I was thinking that this would not be an issue and might help with ejection. Just my theory. Experiment tomorrow evening when ammo arrives.

 

[Texas1911]

You'll just have to try it and see.

 

[Driller]

It seems such a common sense thing to do I figured someone else already tried it.

 

[SC-Texas]

Definitely test it, post video and results.

On the plus side, the can will increase back pressure.

On the negative side, make sure each and every shot clears the barrel as I have seen subsonic 5.56mm stick a bullet in the barrel.

On another note, I wonder what would happen if the bullet just puked out the barrel and dropped into the can between the baffles and was followed by a supersonic round? I would guess the turbulence would kick the free bullet around and make it a rattle can.

 

[SC-Texas]

Btw: Nice Sig 556! Whose stock did you go with?

It looks like an ACE sidefilder

 

[Texas1911]

On another note, I wonder what would happen if the bullet just puked out the barrel and dropped into the can between the baffles and was followed by a supersonic round? I would guess the turbulence would kick the free bullet around and make it a rattle can.

I don't think it'd do much of anything.

 

[SIG_Fiend]

Hmm, I'm curious now. With the gas pressure turned to the high setting, and if you're shooting it with a can on there, that just may be enough overall increased backpressure to still cycle the action. Let us know what you find out!

 

[shipwreck]

Man, that looks nice!

 

[Driller]

Well worked about 70% of the time. Still some ejection issues. Worth the try.