Out of interest I decided to see if could replace the hard(er) to get smokeless powder with something more readily attainable. I’ve always had a fascination with matches so I bought a box from Tescos. After carefully scraping the heads off about 1/2 a box and then crushing them with a spoon (be careful they will ignite, so very small quanties and wear gloves and eye protection).
I packed a acrylic tube with the pink powder and sealed the end with epoxy. After 10 mins I hung it up and did a test fire :
Bit of a result.
Thanks for a simpler solutions. I am also so much concerned about my payload getting lost. 🙂 And waiting until the balloon to blast might affect the distance between the landing site.