Re: Highly Accurate Powder Weights
This subject bugs the hell out of me, please do define "accurate to .1 grain".....
Is it because that's the finest increment found on common powder scales so thus it's assumed that's as "accurate" as the scale can possibly be?
Or, is it that users of such scales fail to be precise in their use of such scales and blindly settle for some degree of +/- accuracy from there scale?
For what I term as precision shooting with my precision rifles, which may or may not be precision shooting or precision rifles by other's standards, I've always weighed out each charge of powder with a beam scale. When I settle on a load for any particular rifle, it's pretty cut and dried on the charge weight. When weighing out that charge, simple logic applies. It's one of three things, either not heavy enough, right on the mark, or too heavy, according to the scale.
Knowing the difference between the three is a simple matter of seeing if the beam pointer aligns with the mark, or not. Elementary I know, but we still have the question arise, don't we. If the beam pointer is above the mark by <span style="font-style: italic">any</span> amount the charge in the pan is too heavy; the cure, remove some powder. If the pointer is below the mark by <span style="font-style: italic">any</span> amount then the charge in the pan is too light; the cure, add more powder. If the pointer is perfectly aligned with the mark then it's a safe bet the charge in the pan is exactly what you need....load it.
"Accuracy" to .1 grain be damned...it's operator error if the scale isn't measuring precise loads. Either the damn pointer is on the mark, or it isn't. Either the fucking load is right, or it isn't.
A smart reloader will realize what induces error into the equation that can and will skew a scales results, and be vigilent in reducing or eliminating them. Dirty pivots, dust on the beam, dust/dirt in the pan, air flow in the area, magnatism of the pointer dampener, etc.
With the above addressed as routine care of my scale, I go the extra step and eliminate what a lot of people overlook, the error of improperly zeroing the scale. I'm not saying that people don't know how to zero a scale; most everyone knows the basic function of setting the beam to zero and adjusting the elevator to reach a point of "zero".
The mistake however, is just running with <span style="font-style: italic">that</span>, assuming the scale will be zero'd forever from that point; or, some will think about it mid way through a run and slide the weights back to zero readjusting if "necessary". My finding with doing it that way is that it's <span style="font-style: italic">often</span> necessary to readjust zero. With "necessary" coming from our own mistake of moving shit around and actually changing something about the scale to cause it to read a hair off from what we <span style="font-style: italic">thought</span> was "zero".
To take the error out of "checking zero", which I feel is obligatory if precision is wanted, I do it without moving any of the parts of my scale. For example, in my 30-06 with 190 SMK's I run 57.0 grains of H4350. Although my OCW load work up tells me that a +/- of nearly .5 grains on either side that 57.0 grains will still impact in an acceptable manner, I feel I owe it to myself to be as precise as possible when weighing out charges. To do that I've made an aluminum check weight, that at the time I made it weighed exactly 57.0 grains, and as long as I don't change it, it always will.
This check weight resides in the die box for that rifle and is stamped with 1/16" tall numbers/letters to identify what it is. To check the scale during process it's a simple matter of placing the weight on the scale instead of powder, and the pointer will point exactly on the mark, or still "zero'd". In fact, I don't even bother with setting my beam weights to all zero when I start. I set the scale to 57.0 grains, place the check weight in the pan, and "zero" from there with the elevator if needed.
Since I've gone to this method the "accuracy" of my charges has greatly improved and I'm no longer fighting the "zero" on the scale. I'm much more confident that what I'm weighing out is exactly what I want and +/- anything is a non worry.
What people need to understand is that the increments we are playing with here, 1 grain being 1/7000 of a pound, and .1 grain being 1/70,000 of a pound, it's very easy to get fucked up trying to get perfect out of an imperfect system. It's not hard though, to get a level of precision that can be applied to what we require. Accute attention given to the well being of the scale, taking extreme care to not jar the scale during use, using caution and care when setting the pan on the scale and taking it off, not moving a lot of shit around to check zero, and reading the pointer properly, all lend to taking the common beam scale to the limits of it's possible accuracy.
If this is something else, rediculous, like a question of whether or not an increment finer that .1 grains is better, then I'd love to meet the man who could shoot the difference......
