How does this crimper work?

The ratcheting is for repeatability and consistent crimping in a production environment. For Mil-Spec work we would have to send these back to AMP for recertification. They cost like $600+ back in the late 1980s.

You can drill out the cross rivets, remove the ratchet and the tool still works fine for automotive shop work.

I use an old retired one with the ratchet removed for uninsulated crimp lugs.