I have a Mark X magnum length action with Blackburn bottom metal. The sides of the bottom metal match up with the action on the outside. The bottom metal is thinner than the sides of the action so there is a step in on the inside. The follower fits nicely in the bottom metal but is too wide to go into the action. this prevents the follower from being able to push the last cartridge up to the rail so that the bolt can contact it. In addition cartridges hand-up on the shoulder between the bottom metal and the action. Solutions: The interior sides of the action could be machined away to match the bottom metal The follower could be machined to fit into the action, or a bead of epoxy could be set to fill the corner between the bottom metal and the action- this would allow for smoother feeding of cartridges but still wouldn't help the final cartridge. I'm reluctant to machine on the action, but if that is the best cure, I can have it done.