Double base smokeless gun powder contains the following elements:

Smokeless powders: They produce much less flame and smoke and are more completely burnt than black powder. Three types; Gun cotton: Consists of nitrocellulose Double-base powder: Consists of nitroglycerine and nitrocellulose Triple base powder: Consists of nitrocellulose, nitroglycerine and nitroguanidine Semi-smokeless powder is a mixture of 80% of black and 20% of the smokeless type. Ref: The Essentials of Forensic Medicine and Toxicology by K S Reddy, 27th edition, Page 188.