Is the POF gas system the same as the FALs?  And if so is it sensitive to dirt and sand just as the FAL gas system is?

The only similarity is the removeable gas plug and short tube that the piston guides in. The gas plug is right off the FAL actually- as surplus. Smart move. The gas piston assm is a two piece design vs. the one piece FAL piston. It is also not fully adjustable as on the FAL. However you can remove the tappet and reverse it to work with a suppressor as there is typically more back pressure in the system.  The advantage the AR has over the FAL is the dust cover on the ejection port the disadvantage is you cannot adj the amount of gas to motivate the bolt in a sandy condition if so required.

The POF upper, for a piston design, is nicely executed and I like the fact that the tappet is protected in the tube, but it does create a place for build up to accumulate. However there may be enough clearance for the gunk to blow out so it may be a non-issue. I would be more concerned about the bolt carrier and upper receiver getting full of shit and if that happens you are really screwed. Keep the crude cover closed on an AR and you will save yourself some hassle.

Go to the Fal Files and check out 'ol dirty and you will scratch your head about how dirty a FAL can get and still run.


T

The FAL full length piston system is not that sensitive to sand. It was more the bolt and upper reciever that would crud up. The fix that the British came up for silty conditions was to "sand cut" diagonal slots in the bolt and upper receiver to give the grit a place to exit as it moved back and forth.