A balance or scale that is reasonably sensitive is useful but not necessary for the loading of ammunition for all ordinary use. When the very finest long range accuracy is desired, or the ammunition is being loaded with over-charges of powder that develop pressures enroaching upon the margin of safety of the arm, a good scale becomes a necessity. There arc a number of scales and balances selling at from seven to twenty doliars that arc amply accurate for this purpose and, contrary to popular belief, they do not have to be sensitive to "a tenth of a grain." Even though a scale has this degree of sensitivity, it is improbable that the average handloader can load a series of cartridges with such a small tolerance, and the idea that charges have to be accurate to this degree is pure hokum. I do not mean that it is not desirable to have powder charges as uniform as possible, nor that it would not be desirable to keep them uniform within this magic limit of one tenth of a grain; I merely state that such accuracy can not be obtained with certainty, even with a scale sensitive to one tenth of a grain.
Now, in case there are some individuals disposed to rear up on their hind legs over such a heretical statement, let's look at the subject from an abstract standpoint, before going into the practical use of scales and balances. If you have a rifle and ammunition capable of shooting two inch groups at one hundred yards, you can't shoot possibles with it all the time, because it leaves nothing for the human error. 246 Two inch groups and a two inch bullseye is just like putting a two inch plug into a two inch hole. (And there is some question as to whether that can be done.) On the other hand, if the rifle will shoot one inch groups, we can shoot possibles with it frequendy enough to feel gratified and sometimes we will get groups of one inch or even less. The same principle holds true with powder scales. The human clement plays just as great a part in weighing powder as it does in shooting, and there must be some leeway in the accuracy or sensitivity of the scales to take care of it. Furthermore, a scale that may have been sensitive to a tenth of a grain when k left the factory may not be that when you get it and even if it is, it will not stay that way indefinitely. With the powder scales commonly used, it is possible to keep charges within two tenths of a grain all the time and within one tenth of a grain some of the time, provided the scale is in good condition, clean, and is used with care. Anyhow, two tenths of a grain is accurate enough.
Now let's look a bit closer at the practical side of this question. The accuracy of a scale or balance depends upon two things; its sensitivity and the accuracy of the weights used. The sensitivity is the ability of the scale to register small differences in weights with uniformity and precision. This depends upon a number of things, but by far the most important is the knife edge that supports the beam and the bearings upon which it rests. In the more expensive balances that are sensitive to from one hundredth to one thousandth of a grain, these knife edges are very sharp and rest upon bearings of agate or other hard substances, into which the edge can not cut. Such balances are alright for laboratory use, but for the practical weighing of powder charges they are not worth a damn. They are so sensitive that it takes forever for them to come to rest. A person skilled in their use can weigh about two charges per minute and keep the charges within one tenth of a grain (?) but 047 to weigh anything to the limits of accuracy of the balance would tax the patience of Job. Such balances are often mounted on cement bases that pass through and are entirely independent of the building in which they are located so as to be free from any vibration or jar. The normal breathing of a person will disturb them, and their accuracy is too great to be of practical value for weighing powder charges.
IllustraUng proper condition or good sensitivity in a balance. Lower shows index pointer at zero despite efforts to throw it off. Upper Tlew shows a one-tenth grain weight In one pan. which throws pointer off, yet it returns to same position every time. A scale or balance as accurate and responsive as this Is suitable fiVr use with maximum charges.
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