Molecular weight distributions during autoacceleration in free radical polymerization are calculated within the framework developed in part 1. Most macroradicals (living chains) are so immobilized by entanglements that they terminate with short mobile unentangled chains with rate constants independent of their own lengths. In some respects, Flory’s "equal reactivity" hypothesis is recovered, leading to a Flory (exponential) distribution of the living population for most chain lengths N. The instantaneous distribution of the polymer product, psi(d), is a copy of the living one. Its mean length is (N) over bar(d) similar to 1/R(i) where R(i) is the initiation rate. For the shortest chains, psi(d) exhibits power law behavior with exponents determined by short chain termination kinetics and vanishes at N = 0. It follows that psi(d) is peaked at N = z, the characteristic short chain length.