Choke assembly for shotgun

A choke assembly for attachment to the muzzle of a shotgun, comprising:

• a collar having a first collar end and a second collar end, said first collar end being adapted to be connected to the muzzle of a shotgun, said collar having an annular outwardly-facing recess and an internally threaded portion proximal said second collar end;
• a sleeve having a first sleeve end and a second sleeve end, said sleeve being externally threaded proximal said first sleeve end and threadably connectable to said threaded portion of said collar, said sleeve including at least one tapered bore and an annular radially outwardly extending flange on said second sleeve end;
• a tubular slide in surrounding relationship to at least a portion of said sleeve and said collar, said tubular slide having a first slide end having an annular radially inwardly facing recess, said inwardly facing recess and said outwardly facing recess cooperating to form an annular pocket;
• a spring received in said annular pocket and biasing said tubular slide against said flange;
• a ball received in said tapered bore and having a portion extending through said tapered bore;
• a choke having a first choke end, a second choke end, and an external wall, said external wall having at least one indentation, said portion of said ball being received in said indentation when said choke is received in said sleeve, said choke being slidably received in said sleeve.