Scales

[0ne3]

I have a RCBS 1500 ele. scale and a old oil dampered beam scale. To day I checked one against the other. I put 12.7 gr. on the ele. scale then transfered the powder to the beam scale, needed to add 4 more gr. of powder for the beam scale to come up to zero.Has any one else experinced this? Even bulllets weigh differnt, why can not we use bullets instead of check weights. Bullets should weight pretty close as to what there are supposed to be. Thank you for your in put.

 

[ArchAngelCD]

I have a RCBS 1500 ele. scale and a old oil dampered beam scale. To day I checked one against the other. I put 12.7 gr. on the ele. scale then transfered the powder to the beam scale, needed to add 4 more gr. of powder for the beam scale to come up to zero. Has any one else experinced this? Thank you for your in put.

I'm not sure what you mean when you say you have to add powder to "come up to zero." In any case you should check any scale with real check weights. Checking one scale against another proves nothing, both could be incorrect.

 

[wrench459]

I just learned this today.
A brand new minted USA five cent piece weights dead nut's @ five grams.

 

[nettlle]

I use a bullet for a check weight. Been doing this for 52 years.

 

[armarsh]

Dimes are close to 35 grains. Good enough for a gut check.

 

[444]

I agree that you should be using a set of actual check weights if you want the scale to be accurate.

Bullets vary in weight. You can prove this to yourself in about 10 seconds. Weigh several bullets and they won't be the same weight. As far as them being "close" well............yeah, they are relatively close. But no where near close enough for me.

This whole scale calibration and accuracy discussion can lead you down a rabbit hole of what degree of accuracy is good enough. If being within a couple tenths of a grain is good enough accuracy for you, that is one thing. IF you were using THE same bullet all the time as a standard then at least you could get repeatable results. If you just pluck a bullet at random out of a box of bullets to calibrate your scale each time you use it, then you won't get repeatable results.

Real check weights are not expensive. I have a few different sets, one of which is this Lyman set: https://www.midwayusa.com/product/1012877380/lyman-scale-weight-check-set
I am not saying these Lyman check weights are some kind of lab grade precision weights (although they may be for all I know) but, they are closer than just using some random object.

 

[LynJP]

I can say that scale-weight-check-set are not very close. But for reloading are as close as needed. I took my set to the States Weight and Measure and had them check it with 30,000 dollar master measure. They are great deal closer than any digital scale I have used. I have had RCBS, PACK and Dillon. I use a Lyman M-5 beam scale. It is faster than waiting for digital scales to stabilize, also more accurate. A good balance scale is one that when weight is added it should go up, then down, and back up to a stable position. You can see a half of a tenth or less with a beam scale. I use my camera on smart phone zoom in. I found a smart phone stand that I put in front of the scale. You could also use Camcorder attached to a laptop. Eye angles on beam scales can be a big issue. Ether of the two solves the issue.

 

[444]

Give me some examples of how far off these check weights were.
I always wondered about this even though I know it is ridiculous and over the top.

 

[springer99]

Been reloading for over 50years and, to be honest, never felt the need for check weights at all. If I've been concerned about scale accuracy, I've just used a known jacketed bullet or coin and that's always worked fine. Also, took my bullets/coins to my LGS and checked them against other scales there. If they're off by a couple of 10th's, I have no problem and,to be honest, have no idea of which one was right. Scale accuracy also seems to vary across the range, if you're measuring a 15gr. vs. 400gr. weight.

Since I always work up my loads using multiple reference data and watch for pressure signs or hard extraction, I don't care if the book charge says 26.5grs. of such and such, and my best load scales out saying 25.8 or 26.3. Difference guns were used in doing the testing in any case. But that's just me.

 

[LynJP]

Give me some examples of how far off these check weights were.
I always wondered about this even though I know it is ridiculous and over the top.

It has been three or four years, and as I remember, some were very close or right on. I think the one grain weight was off, maybe .01 grams, and one of the 20 grain was off. But all were within 98%. Not enough to make any difference rifle load. It could make some difference on hand gun load with low powder charge. I will say that is with beam scale. But when checking on a digital scale good luck. It would also surprise me if you weight ten different set that were all the same.

 

[Dudedog]

Check weights come in different classes, more accurate=more $
http://balances.com/sartorius/calibration+weights.html


Inexpensive set from Amazon $11
&keywords=check+weights&dpID=411Vciv7zLL&preST=_SY300_QL70_&dpSrc=srch

• Class: OIML Class M2
• Gram Weights: 1 by 50g, 2 by 20g, 1 by 10g, 1 by 5g, 1 by 2g, 1 by 1g
• Milligram Weights: 1 by 500mg, 1 by 200mg, 1 by 100mg, 1 by 50mg, 2 by 20mg, 1 by 10mg

 

[PWC]

On one of the forums I haunt, there was a discussion of digital scales and balance beam type scales. In this discussion, the time for a beam scale to "settle" seemed to be the biggest bone of contention, not accuracy. One contributor said to get a small magnet and put on the table / bench under the pan and the scale would settle faster.

So... I set my old Pacific powder balance up for zero as usual, but with a small magnet under the pan. The scale settled with one swing above and below. I've used it this way ever sense. Evidently, the magnet gives a weak attraction for the pan / pan holder. Whoever thought to try this the first time....thanks.

 

[Nature Boy]

When I'm loading .308 for the most accuracy possible I'm trying to measure my charge weight to within +/-0.02 grains, which is the limit of the GemPro 250 scale. I re-calibrate before every loading session using a check weight and watch for drift during the process and re-tare if necessary.

That's about the limit of my patience and probably exceeds the repeatability of the scale, but I've gotten some consistent down range results by doing it so it's in my routine now.

Some guys that shoot long range bench rest are measuring to one kernel of powder but they're using much more expensive measuring equipment.

 

[hdwhit]

One3 asked:
...why can not we use bullets instead of check weights.

Because that 55 grain bullet you think you have may - based on the last time I check-weighed a batch of bullets - may actually weigh in anywhere between 53.2 and 56.8 grains; hardly the kind of accuracy you want to base the calibration of a precision instrument upon.

 

[Reloadron]

On one of the forums I haunt, there was a discussion of digital scales and balance beam type scales. In this discussion, the time for a beam scale to "settle" seemed to be the biggest bone of contention, not accuracy. One contributor said to get a small magnet and put on the table / bench under the pan and the scale would settle faster.

So... I set my old Pacific powder balance up for zero as usual, but with a small magnet under the pan. The scale settled with one swing above and below. I've used it this way ever sense. Evidently, the magnet gives a weak attraction for the pan / pan holder. Whoever thought to try this the first time....thanks.

How quickly a beam scale comes to rest or settles on an indicated value is a function of what is called dampening and for beam scales the most popular form of dampening used is magnetic dampening. A Google of the term "Magnetic Dampening" should bring up a few dozen hits on the subject. The principal of magnetic dampening goes back a long, long time. In the interest of simplicity dampening comes in three flavors. Under damped where an indicator oscillates above and below a target value and finally settles. Over damped where an indicator takes a long time to slowly approach a target value. Critically damped where an indicator passes a target value and quickly comes to rest on that value. When reading the data sheets on beam scales we generally will find a sentence to this effect: "This mechanical scale features superior magnetic damping that helps provide stable results three times faster than any other three-beam balance on the market".

So... I set my old Pacific powder balance up for zero as usual, but with a small magnet under the pan. The scale settled with one swing above and below. I've used it this way ever sense. Evidently, the magnet gives a weak attraction for the pan / pan holder. Whoever thought to try this the first time....thanks.

How much influence or better put bias does this have on the actual weight results? If for example I place a precision 20 grain weight on the scale, with and without the magnet you mention, will I see a difference in the measured weight? Magnetic dampening does not involve a weight under the pan is why I ask. While it may reduce oscillations will it bias the measurement?

Before I forget the THR Forums Reloading Section includes a Library of Wisdom which has some data on scales and forum member bds has done several very good threads on the subject.

Ron

 

[PWC]

There is no weight under the pan; the magnet is lying on the bench, under, not attached to, the pan.

If you zero the scale with the magnet (magnetic bias, if there is any) with the desired weight, it will be set for the zero. Adding the thrown charge until the balance rezeros has fewer + / - excursions.

Zeroing without the magnet and adding the same thrown charge has many more +/- excursions, which I usually had to hand dampen.

 

[Reloadron]

I understand what you are saying, I just don't understand why placing a magnet below the pan as explained would have any dampening effect? I also assume when you say more or less +/- excursions you refer to oscillations above and below the desired indicated value. However, if it works and you get accurate readings then more power to it.

Ron

 

[fotheringill]

I understand the confusion.

As to check weights, you cannot cheap out on the set. The $20 set of fie or six may very well have 2 o 3 that are off.

I have gone to a beam scale after a PITA Gen 6 and a NIB ChargeMaster that went hinky after 16 months (out of warranty).

 

[drband]

There is no weight under the pan; the magnet is lying on the bench, under, not attached to, the pan.

If you zero the scale with the magnet (magnetic bias, if there is any) with the desired weight, it will be set for the zero. Adding the thrown charge until the balance rezeros has fewer + / - excursions.

Zeroing without the magnet and adding the same thrown charge has many more +/- excursions, which I usually had to hand dampen.

I may have to try this. I use an old Bonanza Model C scale with a plastic beam. It is not damped and is VERY accurate but sensitive to air currents & takes a while to settle. Worth a pack of rare earth magnets from Harbor Freight.

 

[PapaG]

When the v.p. of Sierra gave me a private tour (lucky, not special...me) he challenged me to pick any bullet from any bin on any press that was running and weigh it on the presses electronic scales. IIRC, their standards were +/- .1 grain on match stuff, .5 on others. I found none worse than .1 off. I use Sierra bullets to check my scales. Lyman, RCBS and a Hornady electronic (which I'm growing to love)

 

[Reloadron]

When the v.p. of Sierra gave me a private tour (lucky, not special...me) he challenged me to pick any bullet from any bin on any press that was running and weigh it on the presses electronic scales. IIRC, their standards were +/- .1 grain on match stuff, .5 on others. I found none worse than .1 off. I use Sierra bullets to check my scales. Lyman, RCBS and a Hornady electronic (which I'm growing to love)

Among Sierra's quality control standards are:

1. Weight Control of +/- 0.3 grain.
2. Jacket concentricity of .0000" to .0003" on target bullets and .0000" to .0006" on hunting bullets.
3. 100% final visual inspection for external defects.
4. Roving quality control inspectors perform other dimensional checks at the cupping, draw, trim and bullet assembly operations.

The above quote was taken from: SIERRA STORY SIERRA BULLETS - A HISTORY OF PRECISION.

My own experience with weighing any of their Match King bullets is generally +/- 0.1 grain of nominal weight. Actually according to US mint specifications a brand new (currently minted) dime should weigh 35.000 grains. That does not mean I would use bullets or dimes to check the uncertainty of any of my scales. Check weights, even certified check weights really are not very expensive, at least those used for checking a loading scale. Unless you have a known I don't see using a bullet, even a +/- 1.0 grain bullet as a reliable check weight for a scale having an uncertainty or +/- 0.1 grain.

Ron

 

[thomas15]

I have a set of check weights. For me it's not so much for having a precise mass to weigh, rather it's having a standard to check my scales against from time to time. If my scales are off .003 grains from the national standard that is ok with me as long as they are always off .003 grains.

 

[PapaG]

I also have check weights from two sources, one of which is in a set of balance scales from "the old west". I have found that my Lyman and RCBS scales are quite accurate and repeatable and both have been in my family for over forty years.

 

[rfwobbly]

Even bullets weigh different, why can not we use bullets instead of check weights. Bullets should weight pretty close as to what there are supposed to be.

This conversation stirs up several thoughts that cover a broad range....
• You can't use a bullet becasue most of the time the weight of the bullet is not in the weight range of your powder. You want to use a check weight that's close to your powder weight for the simple reason that the scale could be "off" on either side of the range. So if you're working on 38 Spcl using 6.2gr, then you want to "zero" using a 5gr check weight. If you are loading 223 with 28.4gr, then you want to "zero" with 30gr.

• It's important to remember that a balance beam may not be accurate, but will always read the same as long as the teeter-totter knives are kept clean and sharp. (Sizing lube is a great way to keep the rust away.) Reading the same weight repeatedly is really important if your loading notes cover decades. Can you imaging having to re-test 40 years of pet loads ! So what you want most is to be sure that the 32.7gr you measured in 1980 is the same 32.7gr you're reading today.

• Digital scales can go wonky at any time. And, it doesn't help that the things that can make even a really good digital go wonky (magnetic fields, drafts, voltage fluctuations, etc) can't be seen and give no hint of their presence. So check weights are a must with digitals and need to be used religiously.

• Accuracy is therefore a distant second place to Repeatability. The only time Accuracy even comes into play is when you purchase a new scale and find a disparity. Figuring out which scale is wrong and how long it's been wrong could take weeks. Therefore, the most important thing you can do related to scales is to buy the very best balance beam scale you can afford, as early in your reloading career as you possibly can. Then put that scale in a protected place where it can give 40 years of service.


Just my 2 cents.

 

[armarsh]

I have an old 10-10 that I might use if the world comes to an end slow enough that I need to load shells without power.

Until then I will use my FX120i milligram balance that is accurate to .015 of a grain and responds in a second. Every charge gives me a confirmation that the scale is right on. When I take the zeroed pan off to put the powder in the brass it shows me the negative pan weight. Since it is fast enough I can glance down while pouring the powder and see it.

https://ce-products.myshopify.com/products/fx-120i-reloading-scale-122g-x-0-001g?variant=41172916742

https://ce-products.myshopify.com/pages/about-us

The folks at Cambridge understand reloaders and want their business. A great company to work with.