Tare weight?

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gilgsn

gilgsn

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Hello,

I have a Frankford Arsenal digital scale, and I am a bit suspicious that it might throw a charge maybe .1 to .3 grains higher than expected..
Measuring 8gr of Unique for the 45 colt, with a 260gr bullet and a 4-5/8 barrel gives me 875fps.. A bit faster than I thought..

So, is there a common item that weighs around 10 grains and can be used as a tare weight?

For example, how much does a CCI large pistol primer weigh? Are they always consistent to .1gr?

Anything else I could use to proof my scale without having to buy a second one?

Thanks!
 
Well I have one of those and the zero will creep around after I have been using it for a while. I only use it for seperating bullets now and have gone back to the RCBS 10-10/Ohaus that is so accurate. IMHO you should have a good mecanical scale anyway that can be used as a backup. Then the check weight that you can make (lead shot cut/filed to a weight) can be measured on both and compared. As you can tell I am a big fan of having a backup when the $$ allow me to.
 
You can use a US dime for a check weight. They weight 35 grains. I wrote "35" on one with a Sharpie and keep it on my reloading bench so I can use the same one every time.

(and a nickel weighs 5.0 grams)
 
I use that same scale and I verified mine against a friends beam scale both with and without a tare. I find it is VERY sensitive to battery voltage and does not have any sort of built in warning. If it's giving you inconsistent readings that's where I'd look first.
 
Measure your load dump it into the case then after about 2-3 seconds dump it back onto the scale. Do this a few times to make sure you get the same reading. If you get the same thing +-.1gr be happy & go with it. I could care less if I'm exact as long as I'm consistent.
 
Thanks Blackrock, that weight set is exactly what I needed!

I did notice that the scale took a few seconds to adjust, and always check the charge twice.. Actually, I put every case on the scale, and reset it to zero. Then I pour the charge in the case. If it's under, I add powder manually, if it's over, I dump the load and do it again. Then, I pick the loaded case up, wait a couple seconds, then weigh it again. The case is then put aside in a different location. When all my cases have powder, I inspect them visually for double charges, even though that is very unlikely with my method.. I keep charges within 0.1gr.
It works, but it is slow.. I can't wait to get a Dillon 550 again..
 
Get some paperclips and cut them in different sizes. Weigh them before your scale starts to drift. Get a peice of paper and draw the clip to weight and keep them for reference.

I did this with my digital scale and weighed them on my beam scale and they were spot on.
 
What you want is a check weight. A tare weight is what is assigned to a container that is not part of the product being weighed and used. The weight of your powder pan would be the "tare weight" and is subtracted when the scale is zeroed.

Check weights have been tested against weight standards using a balance scale, the check weight on one pan and the weight being tested on the other. Unlike coins, bullets, nuts, bolts, etc. that have merely been weighed on another scale and assigned a weight value based on that scales reading, check weights actually weigh what they are marked.

If one is concerned with accuracy of weights then use real check weights. They aren't that expensive. Everything else is just a best guess and THAT can be expensive.
 
aml - consistancy is more important than accuracy. If you scale is always .1 grains high, but consistent, then you know what you are putting in the cases. You just watch for high pressure signs (which we are all doing anyways right???) and back of when you see em. That scale isn't accurate, but it is consistent. Now if it wasn't consistent, then you have really big issues.

The weighing of objects while the scale is working just sets a baseline for that scale. If the weight changes, you know that your scale is now being inconsistent, a bad thing. If it weighs the item the exact same every time, you know you are at least being consistent with your charges, even if you're not 100% sure of what the charge is... and hence the need for monitoring for signs of pressure (which we are all doing anyways right???)

I like the idea of making my own little check weights... may have to do something about it. .22lr brass filled with different amounts of epoxy for different weights...
 
From wikipedia
Tare (pronounced /ˈtɛər/), from the Middle French word tare "wastage in goods, deficiency, imperfection" (15c.), from Italian tara, from Arabic tarah, lit. "thing deducted or rejected," from taraha "to reject"[1] weight, sometimes called unladen weight, is the weight of an empty vehicle or container. By subtracting it from the gross weight (laden weight), the weight of the goods carried (the net weight) may be determined. This can be useful in computing the cost of the goods carried for purposes of taxation (sometimes called a tariff) or for tolls related to barge, rail, road, or other traffic, especially where the toll will vary with the value of the goods carried (e.g., tolls on the Erie Canal). Tare weight is often published upon the sides of railway cars and transport vehicles to facilitate the computation of the load carried. Tare weight is also used in body composition assessment when doing underwater weighing.[citation needed]

Tare weight is often accounted for in kitchen and analytical (scientific) weighing scales, which often include a button that resets the zero of the scale to a higher value, in order to measure only the content of a container without measuring the weight of the container itself.
Click to expand...

Tare weight is what all of us weigh when we weigh powder. The pan is accounted for when the scale was built, at least as far as a balance beam scale is concerned. Digitals can use any kind of pan/container, or no container. I sometimes use mine to weigh a letter to make sure it's not over the limit, no pan then.

When I'm sorting lead bullets, I have a special pan that's all it's used for. I don't want my powder pan used, because it would get some bullet lube on it, then it would need to be cleaned, then it would be full of of static! :banghead: :fire: :cuss:

Everybody should have a set of check weights. Lyman and RCBS make a set, some have more weight range than the cheaper ones.

http://www.midwayusa.com/viewProduct/default.aspx?productNumber=612694

http://www.midwayusa.com/viewProduct/default.aspx?productNumber=212586

http://www.midwayusa.com/viewProduct/default.aspx?productNumber=493216
 
Tare weight is what all of us weigh when we weigh powder. The pan is accounted for when the scale was built, at least as far as a balance beam scale is concerned. Digitals can use any kind of pan/container, or no container. I sometimes use mine to weigh a letter to make sure it's not over the limit, no pan then.
Click to expand...

Ahh, no....... That is what the Zero button is for on your scale.. to COMPENSATE for or INCLUDE the Tare weight in you Gross weight #, so that it gives you the NET weight of your product only...... Read the last paragraph of what you posted from Wiki...

This is something that I now do on a daily basis. We have 7 scales on premise, largest at truck scale rated to 100,000 lbs. the remaining 6 are 10 to 20,000 lb platform scales.. We do this all day, everyday...
 
Weigh a dime and a paper clip on a friends balance beam and record the value. Then use them as check weights.

Heck, send me your address and I'll weigh a dime and a paper clip on our lab scale at work and mail them to you with the values recorded.
 
You mean you AREN'T getting exactly the velocity in manual?
Have you contacted the publisher to complain? There must be something very wrong if you aren't getting within 5fps of the stated velocity. You should also call the balance manufacturer and complain.
Sorry to hear abut this horror story. Hope you solve the problem soon. Let us know.
 
gilgsn
I have a Frankford Arsenal digital scale, and I am a bit suspicious that it might throw a charge maybe .1 to .3 grains higher than expected..
Measuring 8gr of Unique for the 45 colt, with a 260gr bullet and a 4-5/8 barrel gives me 875fps.. A bit faster than I thought..
Click to expand...

OIC. I didn't understand that you surmised because you got a higher velocity, your scale MUST be throwing heavy! :):D:p

The list is long on what can cause a higher velocity, the last I would consider is that the scale is off on the heavy side.
 
That's why it's convenient to have two scales and check weights.

The scale I have, actually has a CALIBRATION weight, that you use when you are setting it up for the first time, and if you get consistent errors. If you don't have a check weight, I'd suggest you get one.
 
Hello,

I will get check weights, thanks everyone. By the way, I am not complaining about not getting the "manual velocity." Only wondering if the scale might be a few tenths off.. I get no signs of over pressure, and the cases are easy to eject, with a bit of soot on the outside.. Being new to the 45 Colt, I don't know how much it is supposed to kick. My only indication is the chronograph. 875fps seemed high for 8gr of Unique, so I wanted a way to verify my scale. I searched for "tare weight" on Midway, but didn't know it was called a "check weight." Problem solved, thanks again!
 
IMHO, you shouldn't really care if you scale is dead-on, just that it is consistent. (that's why I think a dime makes a perfectly good check weight -- as long as I use the same dime every time)

If you ever switch to a new scale, you'll need to work up your loads again anyway. :)
 
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