Safety question on potassium perchlorate / AL flash

[novice flash maker]

I have been assembling 70/30 Potassium perchlorate and AL in cardboard tubes with glued ends. Each component is added individually and not mixed until ready to light the fire cracker. Should I have any concern when shaking the mixture to combine before lighting?

 

I've shaken many of these vigorously to combine the two materials. My question is should I have any concern shaking within the closed system to combine. No problems so far. My research indicates that this binary mixing is the safest method since the mixture only becomes active within the closed container. 

 

Will the mixture ever spontaneously ignite when shaking without the spark of the fuse?

 

Thank you for your replies.