Do this for all 24 of the rail caps. Now take your 1 inch boring bit already in your drill and drill into the rail where the rail cap hole are. This will leave room for the pressed metal threads that are in the rail caps. Place the rail caps on the rails one last time and secure them with the screws provided. This will allow you to mount a standard bolt into the pocket ear and it will not be in the way when we install the rails.
Some manufacturers use countersunk screws.
All of this may seem like a lot but all in all it takes around 3 hours to do if you set it up like an assembly line.