Wilson-Clark? That's a new one on me, but the Wilson-Rogers (Wilson Combat #47 series) are stainless steel, and seven round capacity models have a round, "self-lubricating" polymer follower. If there truly is a Wilson-Clark magazine that somehow differs from the Wilson magazines most of us are familiar with, I'd be interested in knowing more myself.
My error -- you're right. What can you tell me about the Wilson-Rogers magazines? I know they are SS, seven rounds, and a rounded, polymer follower -- but how long have they been out? Were they originally intended for one particular type of use?
I expect that the Marines wouldn't have chosen them unless they are extremely reliable and durable.
Can you recommend a source? Any idea about the "going" price for them?