Suppressed gas piston AR?

[Coltcombat]

Wanting to run a suppressor on an AR-15.

I had the idea of a SBR (10.5") for a host. (but I'm not dedicated to that option)
But there are so many options and I'm just now really getting into AR's...

The main idea is the reliably run the can... But these are my 2 favorites?
Should I go...
Gas piston 16"
Gas tube 10.5"

What would y'all folks do?
Im only wanting to use quality pArts on this... Noveske,BCM,etc..

I'm just learning about switch blocks and all that stuff... So excuse me if I seem confused on something. I've been a pistol guy for a while..

 

[CAR-AR-M16]

I run a 12.5" Denny's Operator barrel on my suppressed M16. It uses the standard gas system (not piston) and has been 100% reliable for me in semi auto and full auto, both suppressed and non-suppressed.

 

[338Shooter]

I'd go DI. Piston guns are louder suppressed because the way they vent the gas. They are also unnecessarily heavy and give you more moving parts to fail.

 

[CAR-AR-M16]

I'd go DI. Piston guns are louder suppressed because the way they vent the gas. They are also unnecessarily heavy and give you more moving parts to fail.

I agree. I am not a big fan of the piston AR's. I think Stoner got it right the first time. YMMV

 

[Coltcombat]

Direct impingement it is...
What about barrel length? Will the shorter barrel and gas tube make for a quieter shot?
Or would the 16" be fine? (wouldn't mind saving the NFA processing time..

Also, what about the gasses on the DI, is a Noveske switch block a necessary part for the silenced AR?
What parts might be needed to on the suppressed AR? Lighter spring?

 

[Coltcombat]

"edited double post"

 

[carready]

I like the piston to save time on cleaning. Suppressed gi is VERY DIRTY. I use an 11.5" POF and it is plenty quiet. No hearing protection needed. But a 16" would be quieter.

 

[tyromeo55]

Shorter is quieter. And switchblocks are unnecessary.

ETA. Please read my next post

 

[CAR-AR-M16]

Shorter is quieter.

I disagree with that. The shorter the barrel, the higher the pressure, therfore the higher the sound level. The link below (it is a .mil pdf at the link so I hope you can access it) is from some testing that was done on velocity, pressure and sound level using the same ammo in a barrel that started at 24" and was cut in 1" increments down to 5". The sound pressure level was the lowest at 24" (162.5 dBA ) and the highest at 5" (165.0 dBA).

http://www.dtic.mil/ndia/2010armament/WednesdayCumberlandPhilipDater.pdf

 

[NikatKimber]

Shorter is quieter. And switchblocks are unnecessary.

Only if the ammo is subsonic due to being shorter, AND the ammo was designed to burn all the powder BEFORE the bullet exits the barrel. Which for rifle ammo is not typical.

It is my experience with .22s, that 16-18" barrels are quieter than pistols barrels, as the powder is completely burned at that point.