All I can offer at the moment is SAAMI’s glossary definition:

Action, Pivoting Block – An action in which the breech block pivots in an arc to expose or lock the breech.

guns that use a pivoting block action:

• . . .

 

Footnotes / Sources:

“Glossary ⇒.” Sporting Arms and Ammunition Manufacturers’ Institute. Ed. SAAMI’s Technical Committee. Web. 15-18 Jan. 2011.

 

Question:

• Do you know of a gun that uses a pivoting block action?