Shooter's Bible Guide to Sporting Shotguns: A Comprehensive Guide to Shotguns, Ammunition, Chokes, Accessories, and Where to Shoot by Alex Brant, Paperback | Barnes & Noble®
Shotgun Chokes Explained - a Guide to Markings, Sizes & Patterns | The Yorkshire Gent
Choke Tube Diameter and Constriction Table - WaterfowlChoke
Complete Guide to Identifying Choke Tube Sizes - WaterfowlChoke