No No and NO
You are holding a flask full of powder and dropping the charge directly down the muzzle and if there is a spark where do you think your hand will be while the rest of you is in the ER
Always transfer the charge to a separate measure before dropping down the bore
↑ This is correct ↑
This might be an acceptable risk for some, on their first and only the first shot of the day....
Admittedly..., it may be a very rare thing, an ember in the barrel would mean that you are depending on that inexpensive, brass, reproduction valve, to stop the flame and hot gas and prevent the powder inside the flask from ignition and turning the flask into a grenade.
For a powder
charger, which is the old term for a fixed measure, as it appears from what I've read that a powder measure was what we today call an "adjustable measure"....,
I have used turkey wing bone (still do).
I have used brass nozzles for a metal rifle flask, but attached the threaded portion to a wooden cap and thus made them "fixed".
I have used deer antler (still do).
I have repurposed a modern .45-70 brass cartridge case, by putting a steel eye-screw through the hole in the primer pocket, which closed that hole and gave a metal loop for a cord to attach it to my shooting bag.
I have used a piece of bamboo with one end closed due to the "joint" in the bamboo still being in place.
I have used manufactured, brass, set measures cast with a loop at the base for attachment of a cord.
Lastly I have a copper flask, for use with a hand gonne, that has a tube spout, AND a long cap, and the cap serves as a powder measure.
LD