I bought a mag a while ago that leaked like crazy. I didn't have the bolt stick problems but from what has been said, the nubin seems like a plausible problem. The spring looks pretty compressed as well. My orings and cup seal looked the same as well color wise. It leaked like hell from the rear vent and body/reg union. I've since bought a parts kit from tunaman that resolved all of the problematic issues, and I was all for the wire detent and thought the plastic one was a bit cheap looking. Ive shot with the stock detent and sliced a few balls, I replaced it with the new one and haven't had any issues. I'm one that tries everything possible before spending money but with these if a rebuild kit doesn't do it, you have worse problems.