This is not a benefit at all. If the gun is slamming open upon firing it will eventually damage the gun and could cause a very unsafe situation.

The reason that you think that the action releases by itself is because the action operates on recoil and your resistance to the recoil.

When you shoulder the gun you are pulling against the forend and applying pressure against the slide lock. When you pull the trigger and the hammer falls you are still pulling aginst the forarm keeping it locked up. The moment the charge is ignited and begins to move down the barrel the recoil process begins and your forward arm resists this recoil and actually pushes the forend forward thus releasing the slide lock before the recoil can damage it. Inside the bolt is the locking block. This is locked into the barrel extension and as your arm is pushing the forend forward the locking block is locked into the barrel extension and absorbing the recoil keeping the action from slamming open.

After the recoil process ends you are able to cycle the action by means of the forarm. Attached to the action slide arms (bars running down the mag tube) is the action slide block (what the bolt sits on). As you slide back the forarm it in turn slides back the action slide block. The action slide block moves from under the locking block and pushes the locking block down thus disengaging it from its locking engagement. With out you actually operating the action the gun will stay in the locked position. It should not release on its own.

You can test this by taking an EMPTY gun and placing a dowel rod down the barrel. Pull the trigger with out touching the forarm. Now push the dowel rod against the bolt. It should be not unlocked from the barrel extension and you should not be able to move it rearward with our actually pulling aginst the forarm. If this does not happen then something is either worn down excessively or something is broke.