I made a 250 quadcopter with apm mini. I'm running Arducopter 3.2.1. Initially I tried using the default pid values, it was quite twitchy, roll/pitch rate is 0.080 (lowest possible) later on I decreased stabilize roll and pitch values to 3.000 (cant go lower) It was more stable than before but still, from time to time it started to oscilate insanely when I manuevered agresively or bumped to ground while landing. We tried flying with autotune using the mode switch but when I pulled the mode switch the GCS said autotune on but did not do anything with the quadcopter. however it did not oscilate insanely when I flied agresively. Here is a video of the flight and the exact behaviour that I tried to describe! I would appreciate any help! Thank you all.