I loaded up a C6-5 and a 12″ chute. Then, because I’ve never before seen what it looks like when a rocket fails a swing test, I did a swing test. It failed.
No great surprise. The CG was a little further back than my OpenRocket sim predicted, which means it was just about right on top of the CP. Between OR and some experimental measurements I concluded it needed about 25 grams nose weight (a lot!) to get to around 1.3 calibers stability. It’s a short, fat rocket so maybe that’s overkill, but that’s what I went with.
I used lead BBs, wetted and dropped into the nose with Gorilla Glue added.