Have an old Argentino Mauser with the action
'browned'... Is it possible to easy remove
this old way of 'blueing' ? Orginally these rifles
have 'blank shining' actions. The bolt is OK,
has a stainless steel look.

Read about : "To remove old browning
Immerse the parts (not forgetting to plug if barrels
are being treated) in hot lime water for about
45 minutes. Remove and wipe down, then place in
vinegar for same period. Remove and wipe down with
soft rag, and old browning should go."

Somebody already tried this ?

I'm not sure what the lime water does , perhaps remove oils. But the acid, any acid, will remove the oxide which is what bluing and browning is.

Sounds like a witches brew. Viniger is acidic. What kind of lime. Lime the citrus product is acid , or lime like filtered through ash? There is lime you mix in masonry motour to get a "bite" on concrete.

Maybe someone more experienced with rust blueing can help.

Some people like the brown color blueing.

Oil it !!

Blueing and browning are both oxidation/rust. A bottle of rust remover from an auto parts store will remove blueing. Many other things will also, and a large number of these products will contain phosphoric acid. Cold blues with a phosphoric acid base will remove old blueing as well, sometimes much to the dismay of the user..

I think he is means lime away removers as in CLR. I understand slightly heat to 120 degrees this will remove light rust and bluing. Needs to be throughly rinsed which clean water and dried immediately. Like in an oven.

Cola removes blueing effectively without etching the steel!