I have a 16" Olympic Arms complete upper stamped "SUM 5.56" on the barrel for sale. It is the A2 carbine version with the flash suppressor and Bayonet lug. I am selling the upper alone, no Bolt group or charging handle with this. I believe it is a 1/9 twist but do not know the round count. I bought it used off of a Marine Corps armorer who put it together for his personnal use. Don't think that he put many rounds through it and I have only put about 100 myself. I do not know how to post photos so if it does not work I can email them to you. It has some slight marks on the carrying handle, and a teardrop shaped forward assist, functions flawlessly ready to shoot. Asking $325 shipped.