Originally posted by zepnut: Not a prototype. Bear Archery Deerslayer I would guess it was made in the mid 40's. From what I've been told the letters indicate the poundage.A-10# A-1#B-20# B-2#C-30# C-3#D-40# D-4#E-50# E-5#F-60# F-6#So the EF would translate to 56# I have a Deerslayer marked FJ so it would be 67#