I've built an Estes Interceptor, and noticed that the nominal weight of the rocket is 3.9oz. That doesn't include the weight of the engine. Both the B6-4 and C6-5 list maximum liftoff weight of 4oz. So it seems to me that the rocket with an engine in it is already close to 5 oz, maybe more if one went too heavy on the paintjob. I THINK mine is 5 oz, perhaps a tad over, but my scale isn't that accurate - I need a proper digital scale, not the old scale I have. Yet I don't see anyone complaining about their Interceptors flying strangely or crashing, so I'm wondering if there is more to it than that. I do also have some Quest Q-Jets (D16-6) to try out, and their max liftoff weight is 3.49 oz. I had hoped to use them in this rocket Thoughts?