This topic comes up every so often. The definition is open to interpretation. If a person thinks of the physics involved, I guess the true self opener would have to overcome the weight of the barrel assm, or the action assm. It would need to provide the force necessary to move one assm away from the other, right up until gravity took over. An assisted open would be one where the mechanism provided something less than 100% of the necessary force. I suppose "open" is the minimum point at which a cartridge could be removed, or inserted. Less than a full, end of travel, opening. Certainly separate from cocking.
Ruger RL's are a kind of assisted opener, as the last bit of ejector tension is provided on closing. When the top lever is moved, the gun will spring open a little.
In an earlier discussion of this topic, I think 8 bore said to lay a shotgun on it's side, and move the top lever. If it opens it is assisted.
There is no free lunch, at least until someone harnesses recoil to load the springs for assisted opening.
