mudcreek:

I like Carbon 6's suggestion.

As you might know, the synthetic black powders like triple 7 don't actually weigh as much as the same volume of real black powder but they are designed to be measured like they were real black powder. That is, the pressures they make per cubic inch are (somewhat) similar to the pressures black powder makes per cubic inch. Don't be surprised if a "30 grain" load setting on your powder measure only gives a actual weight of 20 grains of triple 7 powder.

That said, if you set the powder measure to 30 grains and then fill it with triple 7, then weigh it. Record the weight.

Do this at least 5 times to rule out variation in the amount of powder the measure makes. Then, take the average of the weights to get a good usable value. Divide this number by 6 to get a value that represents the "5 grains" increment you are looking for.

As an example lets say your 30 grain powder measure setting poured out the following weights of triple 7 powder:

21 grains, 19 grains, 20 grains, 22 grains, 23 grains. Adding these together gives us a value of 105 grains. This is the total for the 5 fillings of the powder measure so divide this number by 5 to get an average of, 105/5 = 21 grains average.

Taking the 21 grains actual weight, divide this by 6 (to reduce the value from the 30 grains to 5 grain increments) we have 21/6 = 3.50 so, 3.5 grains actual weight of triple 7 powder equals 5 grains of real black powder in power.

Using this 3.5 grain value if you measure out 2 X 3.5 = 7.0 grains actual weight of triple 7 equals a 10 grains of black powder.

3 X 3.5 = 10.5 grains actual weight of triple 7 equals 15 grains of real black powder. 4 X 3.5 grains equals 14 grains of triple 7 equals 20 grains of real black powder.

Once you have done this, using your powder scale, measure out 7 grains of triple 7 on your powder scale. Pour this into your powder measure and adjust it so the amount of powder is flush with the mouth of the measure and lock it in position. Now, you can use this to measure out as many "10 grain loads" as you want.

Filling the powder measure with 10,5 grains and locking it sets it up to measure out your "15 grain" loads, and so forth.

My example above is just a wild guess so don't use the numbers. Weigh out the triple 7 on your scale and come up with your own values.