Whether to use a powder measure or whether to use a powder flask is a subject of many discussions on black powder forums and among black powder people. Opinions vary. In fact I have witnessed some pretty nasty discussions on the matter. Though it is a matter of personal preference, there are safety issues to take into consideration when making your decision.
The first thing to take into consideration is the powder flask. Most powder flasks hold around ¼ pound of black powder or black powder substitute. That is like a small bomb in your hand. All it takes is a good spark to set it off.
Many black powder veterans state that that they have not only loaded their weapons directly from a powder flask all of their lives without an explosive incident, they have never heard of an account of an explosion while loading directly from a flask.
Then there is at least an equal number of black powder veterans that take the additional step of loading the powder into a variable powder measure and then pour from the powder measure into the chamber.
Now for clarification, the danger is present after the firearm has been fired. There is a chance of a burning ember remaining in the chamber. If you pour 30 grains of powder from a powder measure onto a burning ember, it will be an unpleasant experience that could pose some danger, If pouring from a full powder flask onto a burning ember could result in severe burns, and/or loss of vision or a limb or two or even worse.
There seem to be three types of people on this issue.
Some folks fire their rounds, then immediately reload with a powder flask.
Some are a little more cautious and take precautions, but still load directly from the flask. The best precautions are to wait 5 minutes, then use a cotton squab and squab the chambers of the firearm that is about to be reloaded. This technique is relatively, if not totally, safe.
Then some are even safer and choose to powder the powder charge into a device that holds a small fraction of the capacity of a powder measure and then pour the powder into the chamber. The technique is the safest.
Guess which group this safety freak is found in? I hate to sound like a broken record, but if I am going to err, I prefer to err on the safe side. I have no problems with being considered by some as being anal retentive when it comes to the safety of my firearms and my person and those in close proximity to me when I am reloading. That is just me.
Information in this article was comprised from facts and expert opinion found in this thread on the Black Powder Smoke Forum, which is entitled, Is a Powder Measure Necessary?. The discussion is still open, join us.