First grasp the shotgun in both hands and squeeze hard…………Oh wait, we are talking about choke boring of the shotgun barrel! I think most shooters are aware that shotgun barrels generally have some degree of choke, and that “choke” is a constriction of the barrel at the muzzle. 

   Lets take a closer look. History, at best, is pretty clouded, but it would seem that choke bored shotgun barrels were developed at much the same time by an American Fred Kimball, and the well known English gun maker W.W. Greener. These gentlemen started experimenting with choke about 1870, and by 1875 choke boring was the talk of the day at most gun clubs. 

   The basic purpose of choke is to control the size of the shot pattern, and thereby the effective range of the gun. As the shot charge leaves the muzzle, air resistance causes the pellets to start spreading out. 

The cylinder bored gun expels the shot in one “Glob” (  a good scientific term ) and nearly all the pellets are acted on by air resistance, causing a rapid expansion of the shot pattern.

   On the other hand, the choked barrel, that is one having a constriction at the muzzle, will squeeze the shot charge and expel it as a “Squirt” (another of those scientific terms). As the elongated shot charge travels through the air, the front pellets are acted on by air resistance,  while the pellets toward the rear of the column are not so effected. The result is many more pellets stay close together, and impact the target in a smaller area, making a smaller “Pattern”.

   Figure 1, shows by high speed photography, this effect. Figure 2 depicts the various methods of manufacture used to produce a “Choke”. Chokes are made in varying degrees, “cylinder” being the least choke and “extra full” being the greatest amount of choke. The manner of defining the degree