What is with this gas tube?

[Hump66]

Is there really anything to the claim of "correct cycling" of an SBR with this type of gas tube? I came across this and was just curious.

http://www.armslist.com/posts/15314...ts-for-sale-bushmaster-ar15--115-shorty-upper

 

[Glocktogo]

It's called a "pigtail" gas tube. It allegedly retards the gas delivery to allow the chamber pressure to drop off more before the bolt unlocks. That will allow for smoother cycling, less recoil and less wear on internal parts.

For an 11.5" gun, I find that gas port matching, an H or H2 buffer and/or a combination of a Sprinco Red or Wolff Extra Power action spring are enough to get correct cycling.

 

[Hump66]

Yeah I've got an H2 in my 10.3" and have no issues what-so-ever.

 

[txnavalaviator]

looks to be more trouble than what its worth. H2 buffer FTW.