Yes, sometimes needle nose pliers are needed to get a spent casing out... not always, but sometimes... the motor ending up flush with the back end of the rocket just makes it doubly hard though...
Well, the motors are pressed black powder... gunpowder pressed into "slugs" that burn slow instead of burning really fast, instantaneously, as in a gun... SO, if you're cutting on it and it gets too hot, or a spark or something ignites it, or whatever, it WILL burn until the gunpowder is all consumed. The actual propellant slug is a 'fast burning" gunpowder that burns rapidly enough to create 70 PSI or so inside the motor casing... when that slug burns out, there's some slower-burning black powder (formulated slightly differently to burn slower) pressed into a solid chunk on top of that, which burns slow enough to give the rocket time to coast to altitude... because it burns slow, it doesn't pressurize the casing enough to create much thrust... virtually none, so the rocket slows down as it ascends. Then, on top of that, is a charge of fast burning granules of black powder, which burns very fast with a significant "POP!" to blow the parachute out of the rocket... this is held in place by the clay cap pressed into the top of the motor.
THAT's why you don't want to cut or modify rocket motors... plus, it's forbidden by the safety codes governing the hobby... and it's just a bad idea...
Once the motor is spent (been burned flying in a rocket) the casing can be used for any number of uses. As mentioned, with a saw, one can cut engine block rings from it... or it can have a dowel or stick glued into it, which makes it a handy tool for painting rockets, once you install it in the rocket's motor mount... or, if you dig the clay nozzle out of the end with a screwdriver, it can be slid over a launch rod to hold the rocket up off the blast deflector plate a bit to make it easier to hook up the ignitors, and not "soot up" the bottom of the rocket when it lifts off... LOTS of uses for spent casings, limited only by your imagination...
later and good luck! OL JR
