Youtuber Janis Putelis from the MeatEater crew presents a couple of short videos here, where he talks about the various shotgun chokes and patterning your scattergun.
For the newbie, a shotgun choke purpose is to shape the spread of the shot in order to gain better range and accuracy. Chokes are implemented as either screw-in chokes, selected for particular applications, or as fixed, permanent chokes, integral to the shotgun barrel.
In the first video Janis explains the five basic types of choke: Highlighting from the most open or loosest (the cylinder choke) to the most restricted or tightest (the full choke).
The basic chokes:
There are a couple of additional chokes that are commonly used—the ‘extra full’ choke and the turkey choke—which constrict the spread even more. These are primarily used, in turkey hunting, where a very tight pattern is desirable when aiming at a turkey’s head.
Next, video Putelis patterns his shotgun. By doing this you get a lot of good information that can help you in the field. You will know how your shotgun performs at certain distances, using certain ammunition, and the best choke to install for whatever particular game species or style of hunting you’re into.
The basic way to acquire the information for patterning is:
Sources: Wikipedia, Steven Rinella – MeatEater Youtube, Janis Putelis, David Smith