Chocking is constricting device within the barrel at the muzzle end of -
High-Yield Explanation
The synopsis of forensic medicine & toxicology ; Dr k.s narayan reddy ; 28th edition ; pg.no 122 The choke bore present in a shot gun ,the distal 7-10 cm of the barrel is narrow . There are some shotguns which have a small poion of their bore near the muzzle end rifled ,which are called "paradox gun" .