Let's hear from a rod builder. I am under the impression the the action of a rod and the strength of the rod are two different qualities. MH or Heavy are the strength rating. The action has to do with how easily the rod bends.
Maybe someone could explain this properly.
Sorry, I tried to explain it quickly, but sounds like you got it. Im not a rod builder so ignore me if ya want :tounge_out: but ill try to explain.
the m, mh are the strength rating, how mutch it'll take.
the action is how mutch of the rod is actively used
fast action rods the top foot bends pretty easy and then its prettty stiff and hard to bend after that.
medium action rods the top half of the rod bends easy then the rest is stiff and hard to bend.
slow action rods the entire rod will bend like in the ugly stick picture were they try to touch the top to the bottom.
there it two ratings inbetween fast and med and med and slow. Ill post pictures of a fast and slow rod and a medium if i have one.