Are the Sinclair rings the same diameter as Forster? I see Sinclair has lock ring pliers for their rings but don't mention if they also fit Forster. Wish the rings had flats or notches for a hook spanner though.
Hornadys are the best for normal presses but are a little smallish for a Co-Ax (though they do work). Split rings are vastly superior to set screws and sometimes the flats are useful for extra leverage.