I have always swore by my Pacific scale for reloading. It has always proven accurate for me. I used to have two of them so I could check one against the other but the brother needed a reloading set up and I had 3 complete setups at one time and I gave one too him so he could start reloading.
Yesterday I was reloading for my .264 Win Mag so I could work up a load for it. I was loading in 1/2 grain increments from 65 to 68 grains and doing 5 loads each to see what the best group would be. I am planning on taking it Mule deer hunting
this fall have some pretty long ranges, out to 800 yds and a couple places might run 900 yds.
Thats a bit past my comfort range for my .25-06 AI. Not that it cannot do it but it just does not have the energy past 700 yds that I like.
While weighing out the loads very carefully on the Pacific scale I would use a Lee scoop to scoop up the powder from a bowl and then drop it into the pan very slowly until it was about 3/10's grain low and then dribble it till it came up to zero. After about 15 rounds being weighed out I happened to bump the pan and when it settled down it came in higher than the scale would go to. In other words IF I am trying to get 66 grains the scale will show 1/2 grain higher and 1/2 grain lower and this maxed out higher than 66 1/2. So I carefully removed enough to take it down to 66.5. This kind of bothered me so about 6 rounds later when I was doing 67.5 the same thing happened again. Ok, I might be dumb but I am not stupid. This needed some figuring out. I also have a RCBS Charge master with a scale so I got it set up and turned on and warmed up and then started weighing each load. Here is where I could of been knocked over with a feather.
When I weighed each load I found that none of them were right on by the RCBS scale. Some only 1/10th of a grain (maybe 3 out of 25) but the rest of them were as much as 1/2 to 1 full grain off and 3 of them 2 full grains off.
I have always used this Pacific scale for small batches when I was working up a gun to get its best accuracy but it looks like I cannot trust it any more. I even used scale weights to check it prior to using it but somehow it has become inaccurate. I am going to have to take it apart and check everything to make sure something is not bent etc. before I ever trust it again.
In 40+ years of reloading with this scale I have never had this happen.
While writing this I got curious and went back and looked the Pacific over again and found that the balance beam had a slight bend in it so I straightened that and outside of that it looks perfect. I rechecked 5 loads that I did last night against my RCBS Chargemaster scale and found that the scale would weight a load 2/10 high against it and then weight the same load 2/10 low or even right on but never the same twice. Its never more than 3/10 different than the RCBS scale after straightening the beam but it never gives me the same twice in a row. The RCBS said the same thing every time. Maybe the Pacific after all these years and more moves than I can count has developed a grove at the bottom of the notch where the beam balances on.
My instincts tell me to trust the RCBS but I have to have something to test it out against so looks like I am going to buy another balance beam scale as this one is driving me nuts.