The Drams Equivelent markings for shotshells were derived from Black Powder carges. Thus a 3 dram equiv 1 1/8oz load was to produce similar balistics to an actual 3 dram charge of black powder behind 1 1/8oz of shot. 3 drams = 82 grs a 3 dram equiv of smokeless may be as light as 20grs or about 25% the wt of the BP. As the wt of powder is a factor in recoil the heavier BP charge produces more recoil for same balistics as Jim pointed out. Seems most BP availale to us today doesn't produce those same balistics, probably from use of inferior charcoals. "If" however you load to the same balistics, BP will recoil heavier.
