Sort of a "poor man's" mgazine disconnect? Like the Krag or the Springfield, where you can "turn off" the magazine and load and eject single rounds while holding the full magazine in reserve.
I'm actually really surprised that the Steyr gives you the option. It's a hold-over from the days when soldiers tried to pick each other off accross No Man's Land one round at a time, but when the charge came they could switch the mag "on" and make 5 rapid shots before reloading. I've always wondered if that added complexity was worth the effort.
Sounds like the Steyr will hold the mag down out of the way so that a round doesn't get stripped out when you cycle the bolt, but the full mag is still there in the rifle, acting like a solid-bottom receiver sort of, so you can drop a round into the action and push-feed it.
On a hunting or sniper's rifle I don't see much need. If you want to single-load, you just have to eject the empty and then press a fresh round down into the mag before you close the bolt. Works the same way with 3% more effort. Wonder why Steyr feels it is a worthwhile feature?
-Sam
