If the chamber length is NOT indicated 65mm or 70mm you have to assume that it is 65mm until you can have it measured. A 2 3/4"(70mm) shell will easily chamber in a 65 mm chamber but the crimp will open into or beyond the forcing cone raising chamber pressures. Just a reminder that modern ammo even light target loads runs near max chamber pressures to operate modern auto loaders. RST and others make ammo for short chambered 16ga(65mm) firearms.
As far as rifle calibers go it is a crapshoot I have a old drilling back-action hammer gun with .344 bore and .364 groove. This gun has tall narrow lands and wide grooves. Mine is a 9.3x72R.
Last edited by oskar; 07/25/17 06:47 PM.
