Steyr S magazine

Recently I acquired a Steyr model S rifle chambered for 7 mm Rem. Mag. which is marked on the bottom. . I want a spare magazine. The present magazine is a rotary design made of plastic. The Steyr website does not list such an item but it does list a Prohunter model S for 7 mm Rem. Mag. Will this work in my rifle? They also list a 7 mm Rem. Mag. Magazine. Will that work in my rifle? They do not say if it is a rotary magazine.
Midway lists a magazine for SBS or S for long action calibers. Will that work? They do not say if it is a rotary magazine.
Thanks