Measuring powder probably causes more concern among new reloaders than any other topic. And it should. Modern powders are so refined that even a 1/10th of one grain difference can be important in some smaller cartridges.
A little about weights and measures is in order. Grains are the measurement of choice for all reloading. Weights of bullets and powder especially are typically only ever referred to in grains. And there are 7,000 grains in one pound. So a 1/10th of a grain is 1/70,000th of a pound!
How can one weigh powder with that small an increment without expensive, complicated equipment? Reloaders do it all the time!
There are two primary tools used to weigh powder – balance beam scales and digital scales. Balance beams have been around since the dawn of time. Digital scales are a newer technology. All of the major manufacturers of reloading equipment now make digital scales on both ends of the spectrum – inexpensive and not-so-inexpensive. The inexpensive digital scales can cost as little as $25-$30, and more elaborate rigs can cost hundreds, where you enter the weight on a touch-pad and the scale weighs out the powder for you and dispenses it in a little tray you can then use with a funnel to pour the powder into a case.
Balance beam scales are actually more accurate. Why? Digital scales, at least in the price and technology range used for reloading, display their weights in 1/10th grain readings. So as powder is being added to the scale, the display won’t change until it suddenly moves from one 1/10th to the next. A balance beam scale will change literally with the addition of a single grain of powder. It may be practically undetectable, but it moves. There is not “sudden” change from 1/10th to the next. The scale is moving continually throughout that change.
Does that difference really matter? Probably not from a purely safety perspective in most circumstances. But if you are loading small cartridges where 1/10th of a grain really does matter (and they exist – you’ll see them in the reloading manuals), you need to be extra careful. For large pistol cartridges and many rifle cartridges, being ultra accurate is more of a consideration of accuracy than safety, especially if you follow the “golden rule” of reloading and start with a minimum published load and work up. Because the published minimum loads are always going to be safe (presuming of course the firearm is in safe working condition).
But there is one major consideration that is often overlooked, especially by new reloaders. And that is the CALIBRATION of their scale! It can be the most accurate – from the standpoint of adjustability – scale in the world, but if it is miss-calibrated it’s not going to give you an accurate weight! So how does one calibrate a scale? With calibration weights! Lyman makes what I consider to be the standard of the industry. They sell a 10-weight set for about $40. I think it’s probably one of the most important tools a reloader can ever own. In fact, I consider it one of the mandatory purchases. I’ve seen digital scales off by as many as several grains. That’s a discrepancy that could be very unsafe. Without standardized weights to check the accuracy of the scale, you simply don’t know your powder charge is accurate. (See the Lyman weights under “Equipment Reviews.”)
Joel Guerin, Versailles, Kentucky