I wore grooves in the semi-clear pivot "V"s which seem to be made of a very hard nylon into which the scale's balance beam's two steel arms pivot in my Ohaus 505 which I purchased in the early 1960s. I wore them out because I weigh
EVERY charge... and I've loaded a great many reloads over the years.
The scale's pivot arms began to "catch" in those grooves and give me false readings. And so, about 12 years ago, I called Ohaus to buy two more hard nylon (?) pivot V's and was told Ohaus doesn't sell powder scales or parts anymore, but makes scales exclusively for RCBS.
The person with whom I spoke also told me that I would not be able to set up the two new pivot "V's" because they have to be set with very precise air gauges which I, of course, didn't have.
As a result, I purchased a new RCBS 1010 which was their top of the line balance-beam scale at the time. RCBS customer service also sent me those two pivot "V's" because I thought I could get my old Ohaus 505 working again regardless of what I'd been told.
Well... I installed the new pivot "Vs" and, just as they said, the scale still didn't give consistent, correct weights. I fiddled around with 'em for a few hours, but I couldn't get them to work properly so I kept using the RCBS 1010 powder scale which I didn't like as much as I liked the original Ohaus 505 which was of somewhat better quality than the "cloned" RCBS 505 available at that time.
But the whole point of this explanation is to give you an answer to your question about your older powder scale... and "Yes", you CAN wear out a balance-beam, mechanical powder scale... 'cause I did it and it sounds like you may have done it as well.
Take a good magnifying glass and look at those opique, hard nylon (or plastic of some kind) V-shaped pivot arm holders into which the balance beam's two steel pivot arms sit. If you look VERY closely and see "grooves" in those V-shaped holders, they're probably "catching" on the steel balance-beam arms and giving you false powder weight readings just as my Ohaus 505 did. If this is the case, it's "new powder scale" time.
I hope this explanation helps you...
Strength & Honor...
Ron T.
