Scale Weight Check set...now what?


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m0ntels
October 25, 2005, 09:01 PM
I got a weight check set for a lab scale for free, verified them on an university lab scale, and then put them on my Hornady scale.

Depending on where we're testing, it is off anywhere between 2 to 9 tenths of a grain. So now what exactly do I do with this data? I made a chart to keep record of it, but what is the proper way to adjust my measuring? Do I tare the scale to the deviation closest to the charge I am trying to measure? Is a few tenths of a grain significant at loads that arent pushing the limit? Can I fix the scale or have someone fix it?

Hate having all this data and not knowing what to do with it. Hehe :p

Randy

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The Bushmaster
October 25, 2005, 09:05 PM
What kind of a scale are we talking about that we are trying to calibrate? There are soo many factors that effect a scale including the weights starting with humidity and barametric pressure. Need more information...

RecoilRob
October 25, 2005, 09:07 PM
Does the Hornady scale have a shot-filled pan holder (like the RCBS 1010)? If so, you can add/remove shot or substitute others until you get it reading properly.

Jim Watson
October 25, 2005, 09:12 PM
I worry more about it being off "anywhere between 2 to 9 tenths of a grain" than about it beein off any if it were a fixed amount or a fixed percentage. I'd see what Hornady had to say.

m0ntels
October 25, 2005, 10:09 PM
Here's what I got recorded...

weight(grams) converted(grains) actual reading (grains) deviantion (grains)
2 30.86 30.80 -0.06
10 154.32 154.60 0.28
12 185.18 185.60 0.42
20 308.65 309.50 0.85
22 339.51 340.00 0.49
30 462.97 463.40 0.43
32 493.83 494.40 0.57

The weight checks are adjusted with little stones inside, so maybe that 20 gram one if off a tad. The scale itself has a nut on the pan side which I assume is to adjust the balance. If that 20 gram weight is off, all the weights should be within a little over a tenth of a grain from actual weight which I wouldnt think is so bad. Maybe I didnt weigh that one at the lab correctly, or maybe I lost one when I was playing around with them. I'll have to find another scale I guess.

Randy

Delmar
October 25, 2005, 10:30 PM
Before you start plunking money down on another scale, try adjusting the base screw on the left hand side of the scale. I have been using a Hornady scale for some years now, and I can tell you that if the scale is not completely level, you will have the issues you describe.

Make sure the table you have it on is completely level, then level the scale itself before you begin spinning the weight adjustment screws on the right, or pan side of the scale arm. If the table is not level, you will have to adjust the foot screw to make it so. The Hornady is not exactly my favorite, and you might want to look at something else-I use a pact digital scale and powder dispenser, especially for my rifle loads, but if there is a load getting near max, I always check a few in the Hornady scale just to make sure.

Bronson7
October 28, 2005, 01:12 PM
First off, those standards are a bit on the heavy side for calibrating your scale for powder loads. I have the RCBS check weights so I can come very close to a standard that matches my target load. What I do is make sure my scale is perfectly level ( I made a little leveling table for this that my scale sets on), then I select a check weight(s) that most closely resembles the charge I want to drop. I set my scale to reflect the check weights I've chosen, then set the pan and weights on the scale. I then zero out the pointer on the scale using the scale's adjustment screw. I remove and replace the pan/weights a few times to check for repeatabilty.
I set my powder drop so my powder charge lines up the pointer on zero.
Scales have inaccuracies throughout their range of use. Setting up your scale to the desired range is to me, the most accurate way of doing it. Same if you want to weigh bullets. You would just use a heavier check weight.
Bronson7

griz
October 28, 2005, 02:00 PM
Another second to the leveling suggestion. But I think the biggest problem is the check weights themselves. How close are they? If for example, the 10 gram weight is off by 0.1 grams, that will translate to 1.5 grains of error. And as mentioned, the size of the weights is too heavy for finding errors in typical powder charges.

Vern Humphrey
October 28, 2005, 04:06 PM
weight(grams) converted(grains) actual reading (grains) deviantion (grains)
2 30.86 30.80 -0.06
10 154.32 154.60 0.28


What are you loading that would take a 154 grain powder charge?

Your problem is that you're checking the scale at weights it will never see in use. Within its design range (say, 30 to 75 grains), it seems to be quite accurate.

Ross
October 28, 2005, 11:54 PM
Surely, some folks sort bullets, shot and cases by weight, as well as powders.
Cheers from Darkest California,
Ross

What are you loading that would take a 154 grain powder charge?

Your problem is that you're checking the scale at weights it will never see in use. Within its design range (say, 30 to 75 grains), it seems to be quite accurate.

bogie
October 29, 2005, 12:01 PM
Guys, the scale has its place...

1. It's a safety device, so that you don't start out stupid.

2. It's how you _start_ your load. Work up with your powder measure from there while looking for pressure signs.

3. Take notes.

antarti
November 1, 2005, 11:16 AM
Reading this post, and having a Hornady Model M scale got me thinking.

Acquired check weight set, and started checking throughout the range of checkweights.

Everything was DEAD ON. Weighed some 69 sierras, found 2 dead on, dropped them in pan and got correct weight (with check weights added), again, DEAD ON. Everything up to about 200 grains (didn't bother going beyond that) was exactly on the "0".

You have to level that scale and use the screw to then get the beam right on "0" before you even think of weighing anything.

The only things about my scale that isn't exactly "on" are the graduations above and below the "0". A .5 grain addition to the pan showed .3 grains on the sliding scale, but as long as the "0" is good, I could care less.

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