This is a key issue for two-stagers. The problem is not so much what happens on the boost, but rather, what happens when the igniter fires. If firing the igniter causes the igniter to be spit from the motor, it often won't light. Many times, I see people using the nozzle cap to hold in the igniter (with or without a stick). The cap doesn't prevent the stick from getting blown out though.
What I do is glue a couple of strings, like kite strings for example, on the top of the nozzle or the bottom of the bottom grain. Then, when I insert the igniter, I wrap the string around the bottom of the stick and super glue the string to the stick. That keeps the stick in just long enough to light the motor.
Jim
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