The SO76 cakes....especially zipper cakes that i have used seem to be pretty erratic. The 300 shot 8 shape gm654's that i had last year were way...i mean way fast. The label said 8 seconds, the videos had it at around 5 seconds, mine shot somewhere around 3 seconds.
Thanks for this post. Im planning for this cake this year and needed it to last at least 6 seconds or it would be an odd section. I'll probably replace it now.