In firearms, a choke
is a tapered constriction of the gun barrel's bore
at the muzzle
end, almost always used with shotguns
. The exit end of the choke is smaller by some dimension than the actual bore of the barrel. This difference is the amount of constriction. Generally the ranges for chokes will be 0.00-1.15 mm (0.00-0.045 inch), while the constriction for turkey chokes may be as much as 2.50 mm (0.10 inch).
A choke is designed to alter the distribution of the shot as it leaves the firearm. For shooting most game birds and clay pigeons, a desirable pattern is one that is as large as possible while being dense enough to ensure multiple hits on the target.
Field and Clays, article on chokes