Been a Winchester collecter for a few more decades than I care to admit, and the term can be confusing. When introduced, a long production run of a certain model can go through changes yet is still the basic same basic gun. Many times these changes arent for the betterment of design but instead a cost cutting measure. When a certain production run near the end of its life and before the new designs are fully inplimented, the factory will use up old style parts on the newer style. These then become transitional models. In the case of the model 70, this transition was from a difficult to mount a scope early model, then the transitional model designed to facilitate a scope better, yet within a year Winchester once again changed the design to even better facilitate a scope that remained through the remainder years of production. This interem year was known as a transitional model.
