Even with an automatic safety it can be done on any gun on which the top lever does not latch over. Many guns using the Purdey style double under bolt allow the lever to return to center when the gun is open. The lever is then cammed back right by the rear surface of the front lug camming the bolt back as the gun is closed. This will include a lot of European guns. It seems that top levers with a catch are mostly an American thing. I have heard, though I am not certain which ones, that some Ejector guns should not have the hammers lowered in this fashion. It doesn't hurt a Lefever with in frame ejectors, can't say about the ones with forend ejectors.
