This is an excerpt from the "Ursus International Website"
Bear bangers are readily available in Canada but harder to find in the US, is a "Pen-Type" bear banger launcher. As the name suggests, this item looks like a pen, and even has a convenient clip allowing it to be attached to a pocket, or pack sternum or shoulder strap. The body of the "pen" contains a spring and a firing-pin attached to a sliding trigger mechanism. With the trigger pulled back and slipped into the safety lock position, a "banger" cartridge can be screwed into the threaded end of the "pen". The unit is then carried in this way until it is either discharged or unloaded. The unit is fired by thumbing the "trigger" slider out of the safety lock position to the end of the opening it protrudes from, and then releasing it. The firing-pin strikes a .22 calibre blank round in the base of the cartridge, which propels the "banger" roughly 30 metres (35 yards), at which point it explodes.
The bangers compare in loudness to the report of a firecracker shell fired from a 12-gauge shotgun, and they should not be underestimated because of the appearance of the firing unit! They are potentially very dangerous, and have the capacity to damage hearing and to cause burns if used improperly. There is a second trigger lock position that allows the banger launcher to be carried "cocked", but it is advisable that it should only be carried in this way when it is likely to be fired at any moment. If the unit has been cocked in this way, the trigger should be carefully released and guided back to the safety lock position as soon as possible. Never carry the launcher in the cocked position!
The banger launcher should only be carried and used by people confident that they understand its capabilities and limitations. It should be used to scare off a threatening bear, and it is also suitable to be used with other threatening wildlife. However, it is of paramount importance to bear in mind that to drive an animal off, a banger device should be fired in front of an animal, i.e. between it an a hiker, and that misjudgment, resulting in the banger landing behind the animal, will drive it towards the firer! Any user, therefore, should know how to control the range of the bangers. This is achieved through recognising that holding the launcher at a 45 degree angle gives maximum trajectory, or range, and that steeper or lesser angles reduce range. By firing at a steeper angle, the banger will effectively be "lobbed" up, coming down closer to the firer than it would if fired at 45 degrees. Similarly, if fired at a lesser angle, the banger will hit the ground closer to the firer than if fired at 45 degrees. The risk in this is that hitting the ground could possibly cause the banger to break up and not explode, whereas "lobbed", it will either go off in the air or after hitting the ground at falling, rather than propelled, speed.
The best advice is to test the launcher before use, even if doing so uses several cartridges. A user must understand the importance of preventing a banger from going off behind a bear, as that will push it towards the firer. In addition bangers should not be fired directly at bears (or other animals), because of their potential to cause injury; ideally, they should be placed in front of and slightly to the side of the animal. Bear banger launchers are available in many outdoor stores in Western Canada, costing between $14-16. Cartridges cost the same, for a box of 6. Some launchers are sold with a combination of banger and flare cartridges, giving the unit the dual purpose of being able to function as a distress flare launcher. However, this combination pack only provides 2 actual banger cartridges. If you buy this package, be sure to buy a separate box of bear banger cartridges as well, to allow you to practice with the launcher.