I have a Lyman/Ohaus M5, 1,000-grain scale I bought in 1968 in Colorado Springs CO. It has been dragged all over the country since then, and is still accurate to within 1/10 of a grain, just like the day I bought it. It has weighed many thousands of powder charges, bullets, and cartridge cases in those years also!

I'd put it up against ANY mechanical powder scale made today, regardless of maker!!