I went to the gunsmithing FAQ section trying to understand the barrel shank thing and frankly I am still a little confused... Forgive me; I am new here!

I do understand how to tell the difference between the standard shank and the large shank by looking at the barrel nut...

But, am I to understand that there are 4 different types of current production Savage 110 receivers? That is to say, a long and short action with the large shank threads and a long and short action with the standard type threads?

Thank you for your help understanding this.

Gene