Acceleration for a rocket launch

Acceleration versus time data (1000 samples per second) for a rocket (Estes Loadstar II) launch.
Video is taken at 960fps and data is replayed at 1/30 full speed to sync with the video. Only the first couple of seconds of the launch is shown as the data connection to the wireless accelerometer was lost at an altitude of about 20m.

Mass of rocket: 132g
Motor: Estes B6-4

Calculated acceleration (open rocket): 80m/s/s
Calculated Apogee (open rocket): 39m
Calculated Max velocity (open rocket): 24.5m/s