I'm fascinated by this thread because I now realize just how little I know about Theobens. I know the Eliminator (Crow Mag) was the big dog, and the Evolution was more of a mid-powered gas piston rifle. I have heard of the Sirocco but, until now, I had not heard of the Olympus. I couldn't find much else info, even after some review of the most recent edition of the BB of Airguns. How do all of these fit into the Theoben lineup? (setting aside the SLR) And could Chrony testing of these guns definitively prove what model they are,assuming each had the pressure adjusted to the max recommended pressure? Or is it more complicated than that?