I have no idea what brand this is but I have two of them. They are both metal ~120 rounds midcaps and have RS trademarks on the bottom saying "ADVENTURE LINE MFG.CO.INC PARSONS.KS.USA" i was thinking they may be G&P but no idea really.
Hmm, that's why I thought they were g&ps because I knew they made mags with real steel trademarks. For now I think I will go on them being CA because I bought them second hand with a bunch of other CA ones.