This is not the same thing but might be a good place to drop it, in front of new eyes maybe:
The tubular metal containers--large or small, are considered by many to be pipe-bombs waiting to happen. There are threads here discussing such. The trouble is that they have no way to bleed off pressure. One solution is to drill a large hole an cover it with something that will blow out in case of an ignition event. Is no joke, folks have been injured.
And yeah, I prime with my main charge powder, same container no biggie. Dump, shake level/off, close. grease it up (if hunting) done.