![Very Happy :D](./images/smilies/icon_e_biggrin.png)
Anyway, I did see something interesting in there you might have noticed already. At 2:30 you can see a vortex ring exiting the barrel as the disk ruptures. It travels out a good ten feet from the barrel by the time the projectile emerges, then ignites instantly in time with sabot being 'caught' and the appearance of the muzzle flash.
At first I thought the ignition might have been caused by the shock wave Vera produces(somewhat like a thermobaric charge), but there is no delay visible in the timing of the flash emergence/ignition. It would have to be going at least around mach 10 to produce such an effect... detonation maybe?