Don't know if you deep cleaned it or not, but if not, that will probably add a few pellets. Yes, even if it's brand new, and yes, even if the barrel is chrome lined. It always helped my SBEII and m2. Second, simply shooting when it's warmer, i.e. 60 or 70 degrees will also likely improve your patterns. I'd say deep clean the barrel and wait for a warmer day to shoot again before making any drastic changes.
