Trapshooters Forum banner
Status
Not open for further replies.
1 - 4 of 4 Posts

· Premium Member
Joined
·
30,370 Posts
Patrick wrote:

" This is a formula that may be of intrest to some,here. Avoirdupois weight formula from the Bureau of Standards. 27 11/32 grains = 1 dram."


a:

1. Abbr. dr.

a. A unit of weight in the U.S. Customary System equal to 1/16 of an ounce or 27.34 grains (1.77 grams).

b. A unit of apothecary weight equal to 1/8 of an ounce or 60 grains (3.89 grams). See Table at measurement.


b:

[ "You won’t find any definition of a blackpowder volumetric grain from the National Institute of Standards and Technology (NIST), or any other source that I know of. The reason is simple; there is none. Blackpowder has always been measured by weight, not by volume; just like breakfast cereal. You buy blackpowder by the pound, and that is weight, not a “volumetric pound.”

The avoirdupois dram is the unit of weight used to measure black powder. There are 256 drams in a pound avoirdupois, 16 drams in an ounce, and 7000 grains in a pound. 1 gram = 15.432 grains = 0.564 drams. These are all weight measurements, and always have been. Volumetric measuring of blackpowder has never been accurate, and it isn’t today.

A closer look at this mess makes it obvious why volume is not precise. The geometry of blackpowder itself varies by its own granulation size; Fg, FFFg, FFFFg, and so forth. Trying to measure blackpowder (or anything else) by its bulk is tricky. Blackpowder varies all over the place by geometry, moisture content, and even composition percentages. Ian McMurchy published actual weight of 100 gr. volumetric Goex FFg as 101.3 grains, 100 gr. volumetric Goex FFFg as 101.6 grains. (Page 81, Modern Muzzleloading For Today's Whitetails.) Mr. McMurchy didn’t stop there; Pyrodex Select (which is a very large granulation size) weighs in at 63.9 grains, Pyrodex RS at 72.5, Pryrodex P at 73.0, Pyrodex pellets at 74.2, Arco at 94.7, Clean Shot at 85.1, and Quick Shots at 65.5 grains of actual weight. The “Arco” cited is the old “Black Mag 2.” ]

Are a couple of -perhaps- informative quotes from a. an online dictionary, and b. from http://www.chuckhawks.com/blackpowder_volumetric.htm

Used to shoot a LOT of black powder through primitive rifles { J&S Hawkin, Leman Trade, etc. } round patched ball 1 : 92 twist rifling. Caplock then switched over to Flint ( or Flinch ) lock. No "Modern" rifles like TC or any of the other knock-off replicas or the in-line rifles made to shoot slugs with a scope. So your post was accurate insofar as it went but there are things and then there are other things. One OLD way to " measure " a proper charge of FFFg. was to place the round ball on your palm and then pour powder from your horn on top of the ball until the cone formed with powder completely covered the ball. Loaded a few Federal -Paper- shells for turkey shoots using 82 grains (weighed ) of FFFg. DuPont over a Fed. 209 primer and card + fiber plus 1 1/8 oz. of # 7 1/2 chilled shot and an overshot card. That load SMOKED the clay, it also SMOKED the field clear out to the traphouse on a dead calm foggy day.

Thanks for the memories you recalled with your post.

Don Thompson, Littleton CO.
 

· Registered
Joined
·
620 Posts
Cool. But the following also needs to be said, since I've heard many rookie reloaders make a dangerous mix-up:

Just because 1 dram = approx 27 grains, this does not mean that you stuff
(3) x (27) = 81 grains of modern smokeless gunpowder into a 12-gauge hull to construct a "3 dram" load.
 

· Registered
Joined
·
122 Posts
Discussion Starter · #4 ·
Mr. Thompson,

I enjoyed your thread. Thank you for taking the time to post that information.
I found the info,that I posted,while looking for amother formula,totally unrelated to clay target sports. I thought that someone here could make it understandable to me. You have accomplished that. Thank you.

Thanks,

Patrick Swartz
 
1 - 4 of 4 Posts
Status
Not open for further replies.
Top