On the basis of recently developed numeric procedures, the results obtained for the propagation constants k(p) by means of the PLP-SEC method (pulsed laser polymerization followed by size exclusion chromatographical analysis of the chain length distribution) were subjected to a critical reevaluation and reanalysis particularly with respect to the chain length dependence of k(p). In this context the errors arising from a broadening caused by axial dispersion in the SEC were largely eliminated together with other uncertainties in assessing the characteristic chain length L-0 on which the evaluation of k(p) is based. The main result that refers to the bulk polymerization of methyl methacrylate and styrene in the temperature range 25-70 degreesC is that the previously found negative long-range chain length dependence of k(p) survived this procedure to an extent that widely exceeds the known variation of k(p) for extremely short chains and extends over a range of several hundreds of propagation steps.