Yuzo Ooki, Dayu Ding, Masamori Higaki and Tadao Yoshida*
Abstract: Interior pressure in a fireworks mortar and initial velocity for the shot of a no. 3 shell were measured and results were analyzed. The observed initial velocity was mainly explained by the action of the interior pressure during the shot. On the other hand, a delay in pressure propagation in the mortar, the effect of gas flow through the gap between the mortar and shell, and acceleration of the shell just after leaving the muzzle were suggested.
Keywords: fireworks, shot, interior ballistics, initial velocity
Ref: JPyro, Issue 22, 2006, pp3-8
(J22_3)
© Journal of Pyrotechnics and CarnDu Ltd
This article does not appear to say the precise caliber of the shell. It appears to me that a “No. 3 shell” would be a 8.5cm diameter shell. Anyone who has a good reference on converting these values is highly encouraged to comment.
http://sumidagawa-hanabi.com/index_eg.html
No. 3 = 8.5cm
Sincerely, Rutger Webb