I managed to sim it in Openrocket decently well, but the design didn't include the fairings around the fins which increased drag in the tail because I couldn't figure out how to get the shape right. On top of that, I would run a flight simulation on a set of motors and get 850ft or more for predicted altitude, and then run the same configuration again and get less than 200ft. Half the time I had the CG showing up right on top of the motors and it wouldn't move even if I added a pound of weight to the nose. Ultimately, I did do the old reliable swing test and the rocket held up just fine. On top of that, it flew beautifully until the motor mixup caused the early deployment. So, even with it coming up to be heavier than my travel thermos full of six cups of coffee, (I know, a cup weighs about 8 ounces, but it definitely FEELS heavier) it was over stable and flew amazingly.