Calibrating a beam scale

[nettlle]

I have a RCBS 10-10 that I am very fond of. Did some research and found out that beam scales can be calibrated to read within (1) kernel of powder. This kind of interests me. There is only one person that I know does this and he will not work on RCBS scales that are not made in the USA. My 10-10 is not USA made. What's involved in calibrating a beam scale to this level? I am not interested in any supersonic electrical tricklers or scales on how great they are. It's beam scale thread.

 

[drband]

Check out this thread: https://www.thehighroad.org/index.php?threads/beam-scale-101-a-look-at-the-tried-and-true.875760/

Should answer all your questions!

 

[film495]

you'll need check weights. I did an adjustment on my old beam scale to calibrate it by adding a tiny dot of clear coat poly to the small adjustment weight. Well, I added the tiny bit of weight after I cleaned and refirbished the whole thing. It was just a touch off and maybe I scrubbed that tiny little metal weight a bit too hard and removed a touch of material. poly was probably not the right material to use, but it was sitting in front of me when I needed something, so - is what it is.

 

[The Happy Kaboomer]

Remove the bottom white pan. Remove the screw that holds it together........Add or subtract birdshot(pieces) to bring scale into balance.......Had to recalibrate mine several years ago.

 

[kmw1954]

I am using a Lyman D5 which is basically an Ohaus 5-0-5 with just the 2 poise weights. Would like to find one with the 3 poise adjustment.

 

[Ekyle]

As Happy Kaboomer said. Re Zero by placing birdshot in the silver holding pan.

 

[N555]

Beam scales have very high accuracy but not super great precision.
I checked my redding 5-0-5 scale against a very expensive digital one. Found that the high gain scale (5 to 440gr) was dead on all the way across.
But the low gain scale was off by 0.2gr across its 0 to 5gr range. So at 0 it's dead on, but by 2.5gr it's 0.1gr light, at 5gr it's 0.2gr light so 5gr on the 0-5gr scale is really 5.2gr. I discovered this may years ago when load developing for 45acp, if I worked up to 5gr on the low range scales and zeroed the low range switched over to one click on the high range I was off by 0.2gr, the same charge suddenly became 5.2gr when all I did was switch to the high range.
As far as accuracy goes it will drop charges accurate to one kernel of imr4350.

I load developed lots of my loads by then with out knowing so I just ignore it.
So the most a rifle load could be off by is 0.2gr which is nothing. Handgun loads could be off by up to 0.2gr could be something a 44mag load using H110 powder, 0.2gr is nothing, but say a 9mm loaded with nitro100nf that could be something. But working up loads properly you won't blow up.

 

[jmorris]

I added photo electric switches and proximity switches to sense beam position.

Makes stock 10-10’s and 5-0-5 scales resolve a single kernel (~.02gn for extruded powders).

This is a 10-10 with a proximity sensor.



A 5-0-5 with a photoelectric switch.



Both are controlling gear motors connected to the trickler. That A&D in the 2nd video is displaying to the hundredth of a grain.

The parts do make one (assuming you already have a beam scale and tricker) are less than $50.



Scott Parker is a fairly well known “tuner” of 10-10’s but by the time I tracked him down, I already figured out mine were already that sensitive, even if my eyes no longer were.

 

[armoredman]

I bought an RCBS Check Weight set years ago, almost by accident, and it has been one of the greatest tools I ever had. I am the opposite - I traded my 505 for a 10-10, and was VERY unhappy with it. When I scored an original 1970's Ohaus 505 in a reloading haul, I sold off that 10-10 as fast as I could. I had a digital scale from Berry's for a while, too, and it had the wandering zero that drove me nuts - I GAVE it to my favorite pawnshop.

 

[nettlle]

Check out this thread: https://www.thehighroad.org/index.php?threads/beam-scale-101-a-look-at-the-tried-and-true.875760/

Should answer all your questions!

A good read. Thank you!

 

[Yankee1986]

I added photo electric switches and proximity switches to sense beam position.

Makes stock 10-10’s and 5-0-5 scales resolve a single kernel (~.02gn for extruded powders).

Honest question.
Can you notice the difference when your charge weight is off .02?

 

[jmorris]

Honest question.
Can you notice the difference when your charge weight is off .02?

Not with a good load at normal distances. With a good load the node might be several tenths.

Many 100/200 yard benchrest matches have been won with volume thrown charges.

 

[cptjack]

Remove the bottom white pan. Remove the screw that holds it together........Add or subtract birdshot(pieces) to bring scale into balance.......Had to recalibrate mine several years ago.

that is balancing the scale read what PROJECT 355 HAS TO SAY ABOUT CALIBRATION

 

[FROGO207]

Firstly you want to thoroughly clean your scale. Then check the knife edges for imperfections, rust or that they are out of square. Test it for repeatibility in the ranges you plan on using it. Lastly rather than tuning it get a set of check weights and see how close each measured weight is when testing in your use ranges. Make a cheat sheet to fine tune (offset) your balance to obtain correct actual weight.