Update of Discovery Limits for Extra Neutral Gauge Bosons at Hadron Colliders

We study and compare the discovery potential for heavy neutral gauge bosons (Z') at the various hadron colliders under discussion at Snowmass 2001 which range in sqrt{s} from 14 TeV for the LHC to 200 TeV for a variant of the VLHC. Typical search limits for pp colliders are ~0.25-0.30 times sqrt{s} assuming 100 fb^{-1} to 1 ab^{-1} of integrated luminosity with some variation due to differences of fermion couplings in the different models. Discovery limits at the Tevatron are ~1 TeV for 15 fb^{-1}, approximately 30--50% higher than this rough guideline, due to the higher q\bar{q} luminosities in the p\bar{p} beams.