So, I have been constructing a very small 24mm minimum diameter rocket recently. I was going to fly it on an F240, but the idea of loosing a 24mm 3-G case made me rethink the idea. An SU F30 will get this one up way further than the eye can see it, so I think I'll stick with that.
Anyway, I was playing around in OpenRocket, and I noticed the "Cal" number at the top. I usually just built my rockets so that the spin-test made it stable, but this time, I wanted to do it the "Right" way. Anyway, my rockets usually sim out with the "Cal" at around 0.6 or 0.7. Apparently, I should be looking for numbers between 1 and 2. All my rockets flight straight as an arrow with this margin...
In order to achieve a cal of around 1 with an F30 in this model, I had to make my nosecone weigh nearly 54 grams... Which is a TON.
A picture, for reference:
It just feels to me that because this rocket is going to go crazy fast off the rod, that I can go for a Cal of around 0.5 or 0.6 and still remain stable. Then again, The last thing I want is a screwball 24mm motor.