7magcreedmoor
Well-Known Member
Don't drive yourself crazy over the chrony or the scale. I use the same old fashioned three poise balance beam scale that came with my RCBS starter kit, after having tried a couple different digital wonder-scales. Why? The electronic scales each "drifted" off zero after anywhere from 7 to 20 charges, and I don't mean by a tenth-grain or two, but by two to four whole grains. Having to recalibrate in the middle of a batch of charges was, as you have found, frustrating. Using the same test weights to calibrate the digitals and check the balance beam, the balance beam was never off, the digitals always wandered- so I got rid of them. I use my powder measure to throw a charge about a third of a grain under the desired weight, then trickle up on the scale to finish. Takes an average of 25 seconds from funnel to funnel. Now, about the chronograph: when we consider what we are trying to measure with a chrony, and how we are doing it, it is amazing that we get useful data. "Seeing" the shadow of the bullet pass over two sensors (or three depending upon your brand) spaced a certain distance apart and then doing an elapsed time calculation to obtain velocity- pretty amazing. Any chronograph that we can afford as typical sportsmen is going to have some error factor, maybe as much as 3 to 5%. Good enough to determine short range trajectory, but for LRH fans, we must do trajectory validation as our final step. Use the velocity average from your chronograph as a start, then shoot short, mid- and long-distance targets in one session and run the actual drops back through your ballistic program to correct your velocity (unless the BC figures are in doubt, in which case you can modify that variable instead of velocity, but don't try to mess with both variables at once) and produce a new "validated" drop table that matches your observed performance. The ballistic calculator on this site has a validation feature that works very well, if you haven't checked it out, take look. I don't know if Magnetospeed is more or less accurate, but it does look to be much easier to set up and use. I would still do the validation process before going on a hunt, no matter which gadget I had.
