WOW ! Chas actually had luck with FSI E60's ?
I learned VERY quickly NOT to risk any rockets I valued on those disasters.
I lterally had over a 60% cato (M-80 style !) rate with those nightmares labeled as rocket motors. The last 5 or so of them I had I glued dowels to them and launched like a bottle rocket. ONE launched, four catoed on the pad.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, TURMOIL, FIASCOS, and HAVOC !