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.

ive been weighing my charges ever since i got my scale. Its a lot more consistent. Throw 70gr weight pyrodex rs on there and its good to go. Its slowed down my shooting but i actually enjoy that time loss, slows me down and i shoot better.

When I work up a load on a new gun, I usually take my scale to the range. When the load is found, I go back to the shop and make up a measure to hold that weight. Generally using 3/8 or 1/2 inch diameter copper tubing which is plugged and pinned at the base.

If you have a number of powder measures, just for kicks, measure out 100 grains in all of the different measures, and then weigh them charges. The difference will surprise you.

i always use the sameadjustable brass powdermeasure. My measure is filled and the struck off level with my finger:No tapping or anything else is done. Tried weighing my charges of Goex Pinnacle for awhile. i got groups thataveragedone quarter inch smaller at 100 yards and decided it was not worth the hassle.

You don't even have to weigh the charge to know there is a difference. My brass CVA measurer will not fill to the top when set at 100gr when I dump my filled TC U-View set at 100gr into it. Haven't weighed the charge but there's a few grains difference.

I have noticed also that the t/c u-view holds the least powder at a given setting. The brass measures seem to be about 5 grains more and I have a clear measure with red writing on it (I think it is a CVA brand) that is about 10 grains more. You would think a certain volume should be a certain volume but it aint. Kind of like 50 caliber isn't always the same.
Art

When manufactures give "maximum powder charges" are they going by weight?

No, they are talking volume. With muzzle loaders, all statements and discussions about powder charges are automatically assumed to be volume unless the author specifically says it's a weighed charge.

That is good to know.