This report is intended to be a follow-up to FERIC TN-58 "using circular saw felling heads to reduce butt splitting damage". In TR-56, shift-level production data have been collected and analysed for the Harricana and Koehring circular saw, the Denis SJ-24 twin saw, the Boreal DD-20 double-deck saw and the Lokomo cone saw felling heads. The five felling heads are compared side-by-side on various criteria such as carrier and hydraulic requirements their operational and mechanical aspects, butt splitting damage, smoothness of cut, stump height and kerf width.