Say your main deployment section is 7.5" diameter, 24" long and using three (3) 2-56 nylon shear pins. How much BP? Also, what's the advantage of using two or more deployment canisters instead of just one? For multiple canisters, would you wire in series or parallel? (One 9 volt battery and Perfectflite WD altimeter with main deployment at 1100'.) Richard DierkingBTW: Kurt, we're not intending to turn the nose into a second stage :-)