He's using a flask with a spout that holds a defined amount of powder. You push the button while holding thumb over spout opening to release powder into the spout, then close the button to seal the flask, and then pour the measured contents of the spout into the chamber. You can get different sized spouts that swap in and out for different amounts of powder charges. Saves the step of filling a powder measure, which I always find to be a good way to spill some powder, anyway.
I know. I've used one for years and have different spout lengths, but would never load that charge into a recently fired cylinder. It's odd that people are so paranoid about filling revolver chambers with grease after loading a tight-fitting ball in order to prevent a chain fire, but would trust the spout valve to close completely and prevent a half-pound of black powder from going off in their hand.
If that's what he's doing you have a valid point. Keep in mind, however, that what occurs next in a video may, in real time, have taken place after a considerable interval.
I do this method every day at range.
As a cowboy action shooter, I pour directly from my Colt style flask with a measured spout and valve. I'll shoot my stage, (typically 10 shots from rifle, 10 from pistols & 4+ from shotgun in varying orders) then move to the unloading table and remove any cap fragments and show rifle & shotgun to be clear. Then, I'll take over unloading table duties (observing that guns coming off the line are clear of any hulls or cases, etc., in effect, ensuring guns are empty. While doing this I'll set up my loading stand and begin the process of recharging my pistols. By the time I start this process several minutes have passed, and in over 37 years of competition, have encountered nary an incident, neither mine, nor anyone else's who's using a C&B revolver. I'm not a "here, hold my beer and watch this" type, but neither am I overly cautious where experience has told me I'm safe. I'm not criticising anyone who does it differently, and by the same token I don't accept your criticism that I'm somehow less safe in my procedures.
