My dad had these and said they were tear gas rounds, he got them from another agency during the UFW-Caesar Chavez demonstrations in my home town in the mid-70's. My dad was the Chief of Police then, so it fell to him to call the shots on how to handle the very large groups of protesters and vandals during those weeks, however there was County and State support there for him and his small department. Probably 10 years back I posted pictures of these cartridges and there were many responses, but nothing really confirmed one way or the other that I remember as to what they might really be. I'm not going to fire one off in case they are tear gas! The year is now 2020, anyone want to venture a guess in current times?