Vibration should be detectable on an oscilloscope with a strong permanent magnet and coil setup. This likely will serve to time the firing cycle but direct timing is going to be more difficult and might better be accomplished with a high speed camera. It would certainly allow comparison of vibrations of the systems. I have a dual trace 30mghz oscilloscope, unfortunately it doesn't have capture and would likely need more photography to capture the cycle.

Jerry Liles