All hunters, competitive and other shooters who reload to produce better ammunition, ammunition not commercially available or to just save money would have to surrender all powder, all loaded ammunition and perhaps primers they now possess . Typical calls are for a 3-6 month feasibility study which would recommend tagging methods and their immediate incorporation into the manufacturing process. The fact is that even slight modifications of existing smokeless powder products to improve performance or long-term stability involves extensive research and development. The burning of smokeless propellant is a very complex process and slight modifications can cause dramatic pressure changes. These are certainly a source of untagged powder.
Final sales are in small quantities - less than a case.
ALL cases in a given lot have the same identifying tag. And the tagging of common fertilizer components would have to be done in such a way as to not confound the taggant search at a crime scene. Rushing to tag could risk human life, devalue carefully-stored reserves of powder and primers, threaten the environment and human health. It could lead to registration of all sales, permits to buy and even registration of ammunition sales and individual identification of each cartridge sold to civilian, non-law enforcement buyers. Congressman Schumer has suggested numerous times the assignment of serial numbers for each individual cartridge and bullet sold and registration of the numbers in a database associated with the buyer.