Arms Unlimited has Colt 6920’s back in stock. So my question is to the 1st Sgt or anyone else who may know, what is the gas port dia on Colt 6920 bbls? I’d like to turn it down to 10.5 and use with a 5.56 can (AAC SR5). So my question is, would this set up still be reliable? Does Colt use a different gas port size on the 10.3″ Mk 18? Or do they keep it the same since this weapon is made to be suppressed and they don’t want to over-gas it?
I am currently running BA (Ballistic Advantage) 10.5″ bbls with this same can. The gas port is approx .070″ and is way over-gasssed with the can. And yes, I want to keep the can for flash suppression in low/no light. If the Colt will run better without resorting to gas block regulators, heavier buffer/springs, etc. then I will consider it.