The Gas Gun or Chemical Agent Launcher was considered second shot accurate in my time. It was made to launch a variety of gas munitions in different dispersal formats. It could fire a cloud of dust, a single projectile rocket like gas missile (these had stabilizing fins on it to control its flight), a scat shell (disperses 5 separate sub-munitions with one round) and several other munitions depending on the requirement. I say “second shot accurate” because your couldn’t rely on its accuracy in the least. Even those few who had extensive experience with this launcher were hard put to get the round where they wanted it to go. The possibility of an accidental strike was always present when firing this device depending on the munitions used and the circumstances of the deployment.  I had used this or ordered its use countless times on the Inside. On the Toronto Police Riot Team we used a different launcher called a Arwen which was more accurate and versatile in munitions. It was capable of launching several rounds of chemical agent as well as bean bag impact rounds.