The very early production ones had some problem with the oils, but it has been remedied. My guess is that Brownells just sent you one from the older stock.
The new polymer being used is safe with all known oils and gun solvents. If you would like to send me that one, I can exchange it for you with one of the newer ones.
Contact me by e-mail off the board, or give me a call at (763)261-5600, and I will get you the details on returning it.