We study the phenomenon of y-scaling in inclusive quasielastic electron scattering. Emphasis is placed on the approach to scaling at finite four-momentum transfers, and the effects of final state interactions. Brueckner-Goldstone perturbation theory for nuclear matter is used to perform a detailed, microscopic calculation of the dynamic structure function of nuclear matter. This is compared to the naive prediction of the Impulse approximation, and we find that the approach to scaling is quite different. The Brueckner-Goldstone approach reproduces the trends seen experimentally (Impulse approximation does not); however, there is still not good quantitative agreement with the data. We take this to be a possible sign of problems in the conventional nucleon-nucleon interactions studied.