hi guys i have on my oly aheavy barrel marked Ss.
what does it mean?
is it chromed? and how many rounds i can shoot usind normal barnaul ammo for plinking?
If it’s marked SS or Ss then it is probably stainless steel.
It is stainless steel. OA does not make chrome lined.
Everything I’ve heard says Oly barrels are actually decently accurate. (Probably in part due to lack of chrome.)
If you want a plinker just shoot it until it is shot out.
A good friend of mine had one of the Oly Plinker Plus’. It had a stainless barrel that was coated. Weird eh?
“coated” how?
I have an Olympic Arms AR with a Stainless Steel barrel. I think his talking about the black oxidizing they do to make them black.
Explanation at bottom of page:
How do I identify my Olympic Arms barrel?
I have more than passing experience with the processes at OAI. 
Most AR barrels are stainless and are then coated in some form or another. Olympic does not do Chrome moly barrels and you would have a stainless steel barrel if it is an olympic. And yes, Olympic is known for their barrels and are some of the best in the industry. Their other products are subject to many, many interpretations as you may or may not know. I’ve had great luck with my Olyarms rifle and love it but I do have several other brands as well and they are great performers as well.
Olympic does not do Chrome moly barrels and you would have a stainless steel barrel if it is an olympic.
Incorrect. 4140 chromemoly steel or 416 stainless steel are used. What they lack is Mil-Spec 11595E Barrel Steel with a chrome lined chamber/bore.