Other than the chemical compound for black powder instead of smokeless, it seems like a fairly well done video for the tyro level video consumer.
It shows, presumably, a Nine Millimeter cartridge, gives some random average facts, indicates the firearm won’t fire until the trigger is pulled, and lists the various components and their jobs.
Yes, the projectile doesn’t wait until the peak pressure to decide to start moving. And, yes, the primer also increases the chamber pressure to “prime” the gun powder charge as it blasts it with a jet of combusting gases, more than just touch it with a spark.
And we typically give the weight of cases in grains, not ounces.
Also, one could fit more than six grains of powder in the case, depending on the powder in question.
These feel like pretty specific terms that an Initiate would be easily corrected on durning their first week of self instruction in Teppo Jutsu. Verily, even a layman’s perusal of more in-depth topics of the nature would find the nomenclature labeled correctly.
Over all though, nothing terribly egregious, I think. What do you find woefully lacking, just for conversation’s sake? I may not be looking at it from the same point of view…