- @ Flyin Brian & rocker98: Thank you both for your help with the barrel measurements. Recently I got a Russian made (Tula arsenal) M1891 socket bayonet (the variant with median locking ring, not the press catch) which had been modified during the 1920s in Finland in order to fit the Finnish M-24 bolt-action rifle with the stepped barrel. I needed to have all the dimensions of the stepped barrel (between the barrel step and muzzle). You also can see my topic "M91/24 socket bayonet" here at http://forums.gunboards.com/showthread.php?256065-M91-24-socket-bayonet Thanks again for the help, Lido 03/21/12 P.S. I collect socket bayonets and the M91/24 bayonet is a rare piece.