I'm not sure. It is a large pin upper though. I can find out if necessary. A relative of mine bought this rifle new about 20 years ago. He recently retired from Law Enforcement in Kalifornia and decided it wasn't worth the BS to keep it. I know that it has been very well cared for although it has some wear and tear from being carried around in a patrol car. It was the first "evil black rifle" I ever shot and is probably responsible for my current addiction.