How do AR15 rifles (not carbines) suppress?

[W.E.G.]

I had a "Gas Buster" on mine.

The vast majority of gas cloud comes out of the ejection port.

I found the gas buster to be about as helpful as a baseball cap in a wind-driven rain.

 

[FullEffect1911]

I found the gas buster to be about as helpful as a baseball cap in a wind-driven rain.

I found that to be true if i didn't go nose to charging handle. But when shooting with irons I tend to do that. It made a big difference for me with NTCH.