Welcome to the forum.

Your gun is clearly model stamped 14, yet the book doesn't list any 4" guns in that serial # range, and none with an all black ramp front sight. I'm thinking you have a standard M-14 that someone had cut down to 4", or had a later 4" barrel installed on.

Either way, you have a M-14 and not a Combat Masterpiece which is the name given by the factory to the pre M-15's, and then to model marked 15's. The 15's have a tapered barrel instead of the full diameter heavy barrel you have.

This is a model 15-3. You can see where the barrel tapers down just in front of the frame-