Ammonium perchlorate-containing gas generant compositions which, upon combustion, produce or result in an improved effluent and related methods for generating an inflation gas for use in an inflatable restraint system are provided. Such ammonium perchlorate-containing gas generant compositions include ammonium perchlorate present with a mean particle size in excess of 100 microns. Such ammonium perchlorate-containing gas generant compositions also include or contain a chlorine scavenger present in an amount effective to result in a gaseous effluent that is substantially free of hydrogen chloride when the gas generant is combusted, wherein at least about 98 weight percent of the chlorine scavenger is a copper-containing compound. Suitable copper-containing chlorine scavenger compounds include basic copper nitrate, cupric oxide, copper diammine dinitrate-ammonium nitrate mixture wherein ammonium nitrate is present in the mixture in a range of about 3 to about 90 weight percent, copper diammine bitetrazole, a copper-nitrate complex resulting from reaction of 5-aminotetrazole with basic copper nitrate and combinations thereof.