RCBS 10-10 inconsistent zero?
After using a cheap digital scale for a number of years, I decided I wanted to upgrade to a more trust worthy scale. All of my loads have been fine, but the Frankford digital just didnt afford much piece of mind.
I purchased a new RCBS 10-10 from Amazon a few weeks ago as well as a set of Lyman standard check weights (.5gr, 1gr, 2gr, 5gr, 10 gr, and 20gr). Following the directions, I was able to zero the scale and check the test weights. Each test weight was within .1gr on my digital scale, but varied as much as .3-.4gr on my 10-10. I check zero again, and find that it has drifted .1-.2gr. Rezero and check again, this time the weights are spot on. To double check, I tested a known powder drop (4.0 grains of tite group, my go to 9mm load). I was quite surprised when the 10-10 read at 4.3. So, I check zero and AGAIN the RCBS had to be adjusted to achieve zero.
Does anyone have any idea whats going on here? I know this is difficult to diagnose at a distance, but im confused about what could possibly be causing this. The scale hasnt been bumped or moved. I've owned 2 other RCBS scales (both 5-0-5's) that I had to return for similar issues. Is RCBS just a poor quality brand?
For the money I am pretty disappointed. I just wanted to see if I was doing something wrong before returning it.