Two years running flawless and all at once checking on 5-0-5 and a Frankford digital 3 grains over. 3 grains less. Calibration passed ok. Getting ready to toss and thought about the LED Florescent light my husband put over our presses. Didn’t think the LED would interfere. Moved the Hornady 8 feet away to another bench and matches the 505 and 2 other digital flawless again. . Sat down to charge about 50 cases last night and checked first few rounds and 6-8 grain differences. Getting gun out of the safe to shoot it full of holes and just happened to see my cell phone a few feet away from it on a shelf. Put the cell phone in another room and back to perfect again. Can’t say perfect because all 3 scales will vary a 1/10 with stick powder occasionally. Just a FYI of things to check before you think of target practice on yours. I’m curious if the RCBS charge master is as finicky. Hornady says 30 minute warm up. I never turn mine off. Every time you delete charge weight and re enter another one you have to re calibrate but that’s quick enough. I was happy with a dipper and a trickier at one time but when it works it’s a life saver for time. A McDonald’s straw in the front tube has never let me over charge but slows down last few grains a little.