how are choke tubes sized — 1 Answer

Chokes tubes come in a wide assortment of configurations. First choke tubes are designed to only be used in the shotgun gauge they are made for. Once you determine what gauge shotgun you have then you need to determine what pattern of choke tube your shotgun is compatible with. For example, these Briley Browning Invector DS Spectrum Choke Tubes are for 12 guage shotguns that use the "Browning Invector DS" pattern or style of choke tube. After that you can decide what constriction you need. Choke tubes constrict the shot pattern as it leaves the barrel. So cylinder chokes have the least constriction and extra full chokes have the most, with a lot variety of different chokes in between. So the most common chokes in order from least to most constriction are: cylinder, improved cylinder, modified, improved modified, full, and extra full.