I personally have original examples of late 60's/early 70's Centuri B14-7's and Estes B14-0's that have cores so narrow that they MUST have been drilled. Any pintle that deep and small in diameter would most likely break under the ramming pressure.
The drilled core is approximately .0625 (1/16") in diameter and quite deep. The nozzle appears to be a standard "B4" profile nozzle diameter and shape.

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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 !