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the Romanians use a different, and hard to find, FSB. IIRC, on the SARs you can 1/2x28, but not 14x1, barrel is too thin.
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You are correct...the Romanians use a 22mm FSB vs the normal 24mm. The easiest way to tell them apart is the bayonet lug on the Romanian FSB is directly below the sight, while the 24mm FSBs have the lug behind the FSB. The Romanian FS is longer, thinner and shaped differently too. Both the Romanian FSB and FS are very hard to find and expensive when you do find them, probably in the neighborhood of $250+ for both.
OP, you do have options though. Yes, you can thread the barrel at 1/2x28, which is very easy to do, or you can use a 24mm FSB and FS. It's what I did to my Romanian AK-74 many years ago because I figured I could then search for a correct FSB and replace the current setup. Well, here I am 15+ years later and have yet to find a 22mm combo.
Compare mine to an Atlantic file pic and you'll see the subtle differences