Hello everyone.  I was just curious about this.  I have never had a chance to look at or handle an Arsenal AK 47.  I have a bulgarian kit built 74 SEAK II from orf, and it has the polygonal type rifling (read that as not sharp lands and grooves we typically see on most rifle bores) but rounded rifling similar to a Glock or HK pistol barrel, or a romanian AK barrel.  My polytech has sharp distinctly cut lands & grooves, typical of most rifle barrels.  What does the Arsenal SAM type AK 47 have?  Thanks for replies.  If I ever do manage to lay my hands on an Arsenal AK around here I will probably buy it on the spot.  Milled AKs are harder to find around here.  

when did Romanian AK barrel have polygonal rifling?  

If you're talking about HK USP type of barrel, I don't know of any AK that has it.  The SAM7 and Classic I've seen are all traditional land and groove type barrel.  The ex-Communist countries didn't use polygonal barreling.

I got my arsenal off of gunbroker because I could not find one in my neck of the woods....

Polyagonal rifling, I am sure, is not the correct term.  What I am talking about is the difference in the sharpness of the lands and grooves.  Look down a romanian 7.62 barrel then look down a Polytech 7.62 barrell and you will see the differrence I am talking about the lands and grooves are not sharply cut and are more "rounded" on the romanian.