I currently have a ragdoll set up and working that I am looking to attach to a mesh to make it appear as if it is riding a horse (setup pictured below).
I’ve attempted to use both Attach Actor to Actor components and Attach Component to Component functionality, which not only does not constrain the ragdoll to the intended socket, but also deforms them by shrinking its mesh parts, pictured below.
You will want a Physics Constraint component for this, it allows for creation of a physical dependency between two other components. It comes with a plethora of parameters that define the behaviour in a granular way.
Best to look up a tutorial first to get the gist of what is what. And then start experimenting: