The approach to Bjorken scaling is considered in a covariant parton model framework and two possibilities are demonstrated. Either scaling is approached like 0(v−1), when all integrals are strongly convergent which may imply that the Regge limit for scaling functions is acieved relatively slowly, or the approach can be like a fractional power. By using parameters obtained elsewhere from pp→ π + X at large transverse momentum it is suggested that scaling is achieved like v−12. For spin-12 models this entails σs/σT ∼ v−12. It is also shown how in the spin-12 case the longitudinal structure function can even scale as occurs in low order perturbation theory. The scaling functions for e−e+ annihilation are also considered and it is verified that non-finite asymptotic multiplicities can be obtained. The constraints of various energy momentum sum rules are carefully studied and it is shown how this leads to the usual parton formula for the asymptotic cross sections for e−e+ → hadrons.