Thread: Loading 7.62x39 subsonic from steel cased factory ammo

you could replace the powder with a subsonic type like trailboss

it would be better to start with a brass case as steel is not what loading gear is made for and possibly could(probably will) damage something like the expander or seater

once you work out how easy it is to knock out and replace the primer this will become a mute point as you are basically just making extra work for yourself this way

opening a rifle bullet up and tipping some out then reseating the bullet is a recipie for an explosion, you need a different type of powder with a different pressure curve (usually a shot gun or pistol powder) but trailboss is easier again as you dont need a packer to hold the powder against the primer flash hole