Abstract: A captured spring recoil buffer has a rod with a flanged rear end and a shaft defining a pin passage slot. An action spring is fitted around the rod and is defined by a forward end and a rear end abutting against the flanged rear end of the rod. A buffer has a cylindrical sidewall and defines an axial bore, with the cylindrical sidewall further defining a pair of aligned crosswise pin openings normal to the bore axis. The buffer is in sliding engagement with the rod, and the forward end of the action spring abuts against the buffer. A dowel pin is positioned through the crosswise pin openings on the cylindrical sidewall of the buffer and through the pin passage slot of the shaft.