It affects the spread of the shot column
A barrel with a full choke.
System of changable shotgun choke tubes made by Mossberg. Accu Choke is their brand name. A shotgun choke is a means of reducing the bore size at the muzzle of a shotgun, to produce shot patterns that spread to a greater or lesser degree.
Cylinder bore- no choke at all.
A pattern of a shotgun is determined by the choke at the factory. Some models have a variable choke that makes the user able to change the pattern.
They came in various barrel lengths and choke combinations. If it is not marked on the side of the barrel, you will have to pattern the shotgun to determine the choke
A shotgun barrel with a cylinder bore choke.
To focus the pattern of shot.
Yes- that is what the poly-choke is for.
A poly choke is an aftermarket choke. The choke twists to different settings. It should have marks to determine settings around the collar of the choke
Depends on the load and what the maker of the choke/shotgun say.
The Choke of a shotgun is the amount of barrel restriction at the muzzle end which affects the shot pattern. A full choke will keep the spray pattern of the pellets closer together farther out than if the barrel was not restricted at the muzzle. If there is no restriction at the muzzle, the choke is said to be cylinder choke or cylinder bore.