As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UPON LIFTOFF NOTICED ACRID SMOKE SMELL AND CABIN FUMES, VERIFIED BY F/A'S. RETURNED FOR IMMEDIATE LANDING, OVERWEIGHT 110, BRAKE APPLICATION 90 KTS. INSPECTED AC FOR SOURCE OF SMELL, NO DEFECTS NOTED. PERFORMED T/O PWR RUN AND NOTICED LIGHT SMELL FROM RT ENG PNEUMATICS. SUSPECT BIRD RESIDUE FROM LAST LEG BIRDSTRIKE. REPLACED BOTH A/C WATER BAGS AS A PRECAUTION.