O-PAP should have a bulged RPK receiver which is what is said in the AIMS description but the picture does not show so. It shows a regular AK receiver without a bulge. Also, I remember O-PAPs would come with surplus furniture instead of new furniture like in the picture, so the AIMS rifle should be N-PAP. Newer N-PAPs are with AK trunions (without bulge) and double stack bolts, older N-PAPs (1st Gen) have grind down RPK trunions (therefore no bulge on receivers) and single stack bolts and imported as single stack rifles and Century modified into double stack by opening the mag openings but did not change the bolts and cause feeding issues. This problem was fixed in newer N-PAPs. 1st Gen N-PAP should be all gone already, these rifles should be the new N-PAPs with double stack bolts, cross your fingers! The only thing is the rifle barrels are not chrome lined like Yugo SKSs. They were in mid-$500s at other vendors recently, so I say pass it!