Rambling Thoughts & Powder Measures
We're always talking about the loads we use. One guy says "I'm using 100 grains of T7 under this bullet" and another guy says "I'm using 90 grains with that same bullet".So, are they actually using charges that are ten grains apart? Maybe. Maybe not. It's quite possible they are using almost exactly the same load. It's equally possible their loads are 15 or 20 grains apart.
It has always been my understanding that volumetric powder measures are calibrated based on FFg black powder. Therefor,allmeasures - whenset on 100 grains and filled with FFg black powder - should throw a charge that weighs"pretty close" to 100 grains, right?Of course, forum regularsrealize that100 grains volume ofPyrodex orTriple Seven will weigh lessbecause those powdersare not as dense as black powder.
Anyway,I was preparing my gear for the upcoming experiment with weighed balls in theGreat Plains flinter anddecided to eliminate as many variables as possible by alsousing weighed powder charges. I've posted many times that this gun favors 95 grains of GOEX FFFg.I planned to filla few dozen of Lane's powder tubes with that load. After setting up the scale for 95 grains, I filled my TC U-View powder measure to the 95 grain volumemark and dumped it in the scale's powder pan. Thatcharge did not even move the scale's balance beam. After making adjustments I found the 95 grain volume chargeactually weighed 84.3 grains. At about this time I recalled thatCayugad once commented thatthe velocities I posted for my 95 grain load seemed low.Sure enough - it's really an 85 grain load. So I proceeded to load my powder tubes with 85 grains weight.
After filling the tubes I began to play around.
I filled the U-View to the100 grain mark withGOEX FFg. That charge weighed 91.5 grains.
I filled the U-View to the 100 grain mark with GOEX FFFg. That charge weighed 89.5 grains.
So clearly, the U-View is throwing "light" charges. Now I'm curious. So I get out my twenty year old H&A brass powder measure.
I filled the brass measure to the100 grainmark with FFg. That charge weighed 95.4 grains.
I filled the brass measure to the 100 grain mark with FFFg. That charge weighed 94.0 grains.
BACK TO THE BEGINNING: Now add in thedifferences in how people fill their measures - tapping/not tapping, pouring quick/pouring slow, etc., and it's easily possible that guy #1'spowder measure set on 100 grainsis actually throwing 105 grains, and guy #2's measureset on 90 grainsis really throwing 80 grains - a25 grain difference. It's just as possiblethat bothmeasures arethrowing 95 grains.