Gas Port sizing on AR15 11.5" barrel

[Omega 5.56]

Does anyone know the recommended gas port sizing for a 11.5" barrel? I believe I'm having an under-gassing issue on my AR pistol and have read that the gas port should be between .086" and .094" for an 11.5", .750" diameter barrel. I measured my gas port and it is .070".

Any information anyone can provide would be great, Thanks!

 

[Omega 5.56]

Suppose I probably should have posted this in the Class 3 section, my mistake.

 

[KDUBCR250]

My 11.5 Daniel Defence barrel has a : .078-.080 gas port. Never had an issue in a couple thousand rounds. Not sure if that's any help or not.

 

[jonny4523]

Who is the barrel manufacturer? What did they say when you asked them?

I assume it's short stroking? Which buffer are you using?