I’m putting together a .308 and want to make sure I’m using the right length gas tube.

I’m using an Aero Precision M5 Enhanced upper receiver and handguard. The barrel is a Faxon 20” Match barrel with rifle length gas system and I’m using SLR Rifleworks adjustable gas block.

I know there are two different length gas tubes (DPMS or Armalite…) even though it’s nominally rifle length.

I have a regular AR-15 rifle length gas tube on hand…will it work?

Thanks in advance!

Faxon 308 barrel:  you want the Armalite AR-10 rifle-length gas tube.

https://www.ar15.com/forums/AR-15/Time-to-diagnose-a-sick-rifle-pt-2/121-772760/?page=1&anc=bottom#bottom

https://www.ar15.com/forums/AR-15/6-5-Creedmoor-build-not-running-until-I-cut-buffer-spring-/121-773940/

will it work?  if the gas port is generous enough, it might.  There was one guy who posted on here, it worked fine, until it got cold outside, then it didn't.  started working again in cold weather when he replaced the AR-15 gas tube with the Armalite AR-10 gas tube.

Interesting...

I have a Faxon barrel rifle length gas with an AR15 rifle gas tube on my Mega Maten and I've had some cycling issues with it in the past but was able to alleviate with the adj gas block, never thought my gas tube was too short. I just checked my rifle and compared them to your pictures, and sure enough, that sucker is too short! Very helpful, thank you!

Hey…Thank You for the info, it’s exactly what I was needing to know!

I just ordered the proper gas tube…