Cordite hasn't been used as a firearm propellant since the 1960's, and it was only used in European manufactured ammunition. Modern ammunition, including shotgun shells use double-based smokeless gunpowder, which is made of nitrocellulose and nitroglycerin. Cordite used nitrocellulose and nitroglycerin although in different amounts and with different additives so Cordite and modern gunpowder do smell somewhat similar though anyone with experience should be able to distinguish the two smells.