Dram Equivalent

Dear Technoid:

Can you tell me how to find out what the drams equivalent is for 18 grains of Clays powder? Is there a conversion formula for finding this out?


Dear Bob,

Here’s how you figure dram equivalency: In 12 gauge, a standard 3 dram load with 1-1/8 oz of shot travels 1200 fps. Each 1/4 dram equivalent that you add increases velocity 55 fps. Each 1/8 oz of shot that you add subtracts 35 fps.

So, if you want to calculate the velocity for a 3-1/4 dram 1-1/4 oz 12 gauge load:

1) a standard 3 dram 1-1/8 oz load is 1,200 fps
2) add 55 fps for each +1/4 dram
3) subtract 35 fps for each +1/8 oz shot
4) 1200 fps + 55 fps – 35 fps = 1,220 fps

I’m not nearly smart enough to figure all this out. Hodgdon has all the dram equivalency information on page 25 of their “Shotshell Data Manual” (the hard cover reloading book).

To get a dram equivalency from the powder charge, just look up the recipe you are using that calls for that powder charge, note the velocity and shot weight, then do the numbers. Nothing easier- except maybe programming the VCR.

Best regards,

Bruce Buck
The Technoid
at <www.ShotgunReport.com>
(Often in error, never
in doubt.)

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