I recently purchased a Cz Bren 2 MS in a 7.62 x 39 with a 9 inch barrel. I took it out yesterday. It was a real hammer but I liked it. Very accurate. I took it apart today to clean. When taking out the firing pin I saw that there was no spring. I had looked up a post that indicated that the Bren 2 "S" did not have a spring but that the, "MS" did have a pin spring. I'm wondering if I did get an MS or an S model. I bought it new online and it was sold as a Bren 2 MS. I'm and very curious about this. Can someone give me clarification on this?