Science behind powder measure baffles

[BigDMT]

This might be a dumb question, but what exactly does the baffle do in a powder measure? I have never used one. Is it just there to maintain a consistent powder flow and weight on the metering chamber for consistent throws?

That is what my logical thinking is bringing me to believe since I do notice a big difference on charge weight once my hopper gets light on powder. But curious if my thinking is correct or not. Thanks.

 

[gambleone]

That's what I always thought. Baffle there to keep the xtra weight of the powder
away from the metering chamber. Filling up the powder measure without the baffle
will result in heavy charges. I don't use the baffle cause it's too hard to empty the
powder back out when finished. I just keep adding a little powder at a time.

 

[SW Iowa Shooter]

Both of you are on the right track. A taller powder supply above the metering chamber will put more powder grains in the metering chamber than a shorter powder column. Similar head pressures on the mixing chamber from the same powder source should throw very uniform weights of powder. The baffles limit the amount of change in head pressure that the mixing chamber will be exposed to as it is being filled. Powders shaped like 3031 have more of a random packing factor and less uniformity in charges thrown than the spherical or ball powders like H380. Measured vibration will reduce but not eliminate the random packing factor. Refilling your measure a little at a time is doing the same thing.