United States, Regions, Divisions, and States: 1900 to 1990 [TXT] United States: 1790 to 1990 [PDF] NOTE: An error in the 1960 rural population count was discovered after the publication of CPH-2-1 from the 1990 Census. The correct 1960 rural population using the 'Current urban definition' is 54,054,425.
Shotgun Choke Tubes: A choke tube is; a removable interior tube at the end of a shotgun barrel that controls shot dispersion. Choke tubes typically come in cylinder, improved cylinder, modified, improved modified, full and extra full.A cylinder choke tube produces a very wide shot dispersion, whereas a extra full choke tube will provide a much tighter shot pattern. Different chokes are used for skeet, trap, and sporting clays.hoke tube selection is a confusing issue amongst a lot of shotgunners but one that is easily explained. Everyone knows how to pattern a shotgun and what they are looking for, which is the ultimate full choke pattern at 40 yards, which is a 70% shot pattern, it is this area where it all gets fuzzy and needs explaining.
An automatic choke is a device that is mounted on the carburetor of a gasoline engine.