Help with Rings

Can anyone identify what make these rings/bases are? I want to go to 30mm rings and am wondering if I can buy just the rings somewhere to suit these bases? Both the bases and the rings are steel, I have seen very similar ones produced by leupold but they had "Leupold" stamped along the side of the bases and these do not. They are on a BSA magnum action if that helps.

http://i1374.photobucket.com/albums/...sfi4f77iw.jpeg

http://i1374.photobucket.com/albums/...sn0l2wobt.jpeg

Thanks in advance for any help.

They are Leupold dual dovetail rings. Any shop can supply normal bases and 30 mm rings to fit. Cheers, Gary.

So in theory these should fit my bases?

Gunworks Ltd - 30mm Leupold Standard Rings

Hey Ryan
No those Standard rings won`t fit your bases. You gotta specify Dual Dovetail. BOTH rings should look like the one on the RHS of Gunworks photo.