is it a close bolt subgun or an open bolt?
The Skorpion Evo 3 is a closed-bolt sub-machine gun. I'm not really sure, but I believe the bot operating system is some type of delayed-action as I remember it.
One thing I did forget to mention in my original post is that this system employs a bolt-hold open device. The device positively holds the bolt open on the last shot. However, this precludes the magazine from falling freely when ejected. I think it's typical European thinking that they would want you to hang on to your mags, thus, this peculiar thing.
If you wanted the mag to fall freely, you would have to grasp the charging handle at the front, rack it all the way to the rear, and then push it up to its stop position ala HK MP5. After doing this, you could then hit the mag release and the mag will now freely fall. Magazines, by the way, are 30-rounders.
If I were to come up with a manual of arms for this system, I would definitely go for the latter actuation so that the mag would fall free. I would then insert a new mag, slap the charging handle so it would go home on its own, then raise the gun up and continue to fire. Just my opinion, folks.