A few questions

[Ravenwolf]

Hello, I hope everyone is enjoying, there summer. I bought a pan powder charger, and the fine print said it was set up using, Goex powder, so since I use Swiss powder, if I am shooting 90 grains, am I really putting in 95. Or is it + or - 3 grains and not worth asking about. Next I have been getting up near 100 shoots and I am finding out about ALL the things associated with shooting, I am getting ready to go to a shoot, DO I use the hunting load or cut it back to a target load ?? My concern is all the time I put into sighting in etc. will be in vein ?  Last I would like to say I have been using the windshield washer solution and a shot of neetsfoot oil and have had zero problems, the Daryl method works. Best to you and yours; Ravenwolf;

[hanshi]

If you're using Swiss you need to drop back 15% or so from your Goex load.  For targets & practice there's no need for heavy loads; work up a light target load.  It will be more economical and easier on the shoulder.

[Daryl]

If you're using around 90gr. of Swiss, you are using the equivelence of about 105gr. of GOEX. That would probably be an accurate load for most any range in a .50 - maybe even a .54. 

If it's an accurate load, shoots nice tight groups at 100yards off a rest, I'd find someone with a scale, throw and weigh a few charges, and record what that measure throws. If you lose it, you can make another or set another commerical measure to throw the same amount.

[T*O*F]

I bought a pan powder charger,

A pan powder charger is a device which deposits 3 grains of priming powder in the pan of a flintlock.  I suspect you are talking about a powder measure.

the fine print said it was set up using, Goex powder, so since I use Swiss powder, if I am shooting 90 grains, am I really putting in 95.

Do not confuse volumetric measure with weight measure.  They told you it was calibrated with Goex, and should have mentioned a granulation, since 3f will be more dense than 2f.  Likewise, in either granulation, Swiss will be more dense than Goex.  As Daryl said, you need to weigh your charges and re-adjust your measure; as you will essentially be recalibrating it from Goex to Swiss.
a. Measure 90 gr of Goex and weigh it.
b. Set your scale to 90 gr and add Swiss until it weighs that.
c. Dump that charge into your measure and adjust it down until it is level.
d. Alternatively, if you want 90 gr of Swiss as your load, just do b & c.

[Daryl]

I took the initial post to mean he bought a pan charger, and noticed it indicated it was graduated to throw GOEX. He then wondered how much his rifle's measure which is set at 90gr. actually threw in Swiss powder.

Granulation size is important as to the actual weight a stricken measure throws, as TOF noted - some powder are more dense than others.  The make/mfgr. of the powder measure is also important - if someone has that make. I am assuming 2 measures of the same make, are marked in exactly the same places and made of the same materials.  Different makes of measures have different diameters and are set up (guessed-at) for measure by different people - hense will throw different weights of different powders. 

Normally 3 to 5 gr. is not sufficient to make MUCH difference in accuracy of a .40 or above, but can still open or tighten groups slightly. As well, it usually means only 30 to 40fps in a .50 cal rifle. In a .32, 5 gr. can make the difference between 2" and 1" for 50 yard groups.  In a big bore, like a .69  there is almost no difference that cannot be noted without a chronograph and if using oil for lube, many shots must be made to see that difference consistantly.