You will find that Nu Line makes a series of choke tubes (Card shooter, Turkey hunter, Trap shooter, Duck hunter, and Quail and Skeet) some have the same choke size but different series. 
The reason for this is we have custom tailored the inside of the choke tube for specific size of shot that is used for different shooting events. 
The angle of the conical section and length of the parallel section are tuned for the specific shot size used for the different events<br>

