There's a fella over on falfiles that has run a FAL through 13,500 rounds so far without a cleaning. I don't believe he has adjusted the gas either. Heres a copy paste of the first post and a link...
Current round count without cleaning:13,500
This is a tale of a legendary rifle from Texas known as Ol' Dirty. The rifle is owned by FAL Files and TX-FNFAL member, James. This is not a story for the faint of heart or for AR-15 owners so read at your own risk.
A year or so ago, James decided that he would conduct a duration experiment just to see how long a standard post ban FAL rifle could go without a cleaning of any kind. The rifle started life as a nice StG 58 kit built on an Imbel receiver with a DSA fake long Belgian flash hider and a spray can camo finish. Since I have known James, the rifle has always been very reliable and accurate and really one of his favorite firearms.
The experiment started as a challange to see if a FAL could withstand continued abuse and filthiness that a less robust rifle could only dream of. Ol' Dirty has had almost 4000 rounds of various surplus ammo fired through it without a cleaning. The chamber area has an incredibly nasty build-up of carbon (it actually now has an almost solid carbon feed ramp). The gas plug is pretty much frozen up from carbon fouling and I don't think the piston has been seen for some time now. The rifle still cycles perfectly and the accuracy is as good as ever. I have shot my rifles against this rifle many times and it is tough if not impossible to beat. Accurate shot placement out to 400 and 500 yards is common for James and Ol' Dirty.
It just goes to prove what the FAL can accomplish under the most extremely filthy conditions.
Update: I have been informed that this was never intended to be an experiment but that James just doesn't like to clean his rifles.
Look in HORROR
http://www.falfiles.com/forums/showt...t=legend+dirty
I think the adjustable gas feature is all pro. It gives you the ability to set your rifle for maximum efficiency/minimum recoil or rifle wear and tear.
If you doubt you have the correct gas setting and you are in a situation where you cant "dial it in" all you have to do is set it at "1" and let her rip.