That saw was a 125. He also cut a desk in half with it earlier in the movie.Paul Newman made several movies in which he operated a McCulloch chain saw. The saddest one showed him trying desperately to save his buddy who was trapped by a huge rolling log in a river. It was an unforgettable scene and a tragedy. I saw this movie when it was released. I was still in college a the time. I believe it was entitled "Sometimes a Great Notion".
I found the movie on VHS a few years ago. It's on Amazon Prime now and Stars, I think. Best scene was the last one. I built my SP125C from spare parts. Also have a 35, 3-25.