The web's most comprehensive user-interactive handloading database! Find the loading data created by handloaders, for handloaders, post your pet loads, or access and develop your own online loading database with our LoadNotes personal handloading database software. This feature, unique in its concept and intuitive in it's data presentation is fast to access, superbly organized and comprehensive in scope.Our online forums for questions and answers on many shooting and outdoor related topics. A dynamic, active, and well-informed resource for your enjoyment and interaction. Our most used resource on this website! Come share the experience with us!
» Advanced

Go Back   Shooters Forum > Handloading > Handloading Procedures/Practices
Register FAQ Members List Donate Calendar Search Today's Posts Mark Forums Read



Reply
 
LinkBack Thread Tools Rate Thread Display Modes
  #1  
Old 03-17-2005, 06:37 AM
Beartooth Regular
 
Join Date: Nov 2004
Location: Indianapolis
Posts: 323
How to check scale accuracy?


Registered Users do not see the above ad.


I just got my Lee Safety Scale last night and checked the weight of powder metered out by my dipper. my 2.5cc dipper was supposed to meter out 34.3 grains of H4895. I tried multiple dips and found they most consistantly measured 33.7 grains. Only two of the seven dips measured anything different and there was one dip at 33.5 and one at 34.1 grains.

So, anyway, the difference between the scale's figure of 33.7 and the volume method's supposed 34.3 has me wondering how accurate my scale is. The scale is apparently very sensitive, remarkably precise, and consistant. I followed the set-up procedure carefully and am positive the scale was zeroed perfectly. But I don't know how to tell if the absolute reading is accurate. I don't have a set of check weights and I'm not willing to spend the money on them at this point. So, does anyone have any other ideas on how to check the scale's accuracy? Any household items that can be used for a test weight or something?

My bullets are all 200 grains and too heavy to weigh in this scale.
Reply With Quote
  #2  
Old 03-17-2005, 07:01 AM
Beartooth Regular
 
Join Date: Jun 2003
Location: Colorado
Posts: 270
Very few things referred to as "household" are going to be small enough and have a precise weight to use for reference.
The Lee "dipper " method would be my least desirable method for powder loading anyway. I would be more inclined to trust the scale than my ability to accurately dip out coarse grained powder.
Find someone else who has a powder scale and compare or buy test weights.
Reply With Quote
  #3  
Old 03-17-2005, 08:11 AM
Jack Monteith's Avatar
Beartooth Regular
 
Join Date: Dec 2000
Location: Saskatchewan
Posts: 7,788
Like skb said. Lee dippers usually throw light, and the scale is more likely accurate. Your drug store might have an accurate scale and check weights too. Weight a dime and take it to the drug store.

You should have a scale that can weight your bullets too. I've found a few surprizes over the years.

Bye
Jack
Reply With Quote
  #4  
Old 03-17-2005, 08:21 AM
UnCruel's Avatar
Beartooth Regular
 
Join Date: Nov 2004
Location: St. Louis, Missouri
Posts: 860
That scale is advertised to be quite accurate, and I've never heard anyone say that it wasn't. I would certainly suspect the consistancy of the dipper before the scale.

Save the money you would spend for check weights and use it to buy a Lee Perfect Powder Measure. It is amazingly consistant and easier to use than the dippers. With short cut extruded powders, I am unable to detect any variation with my scale.
Reply With Quote
  #5  
Old 03-17-2005, 11:06 AM
Swany's Avatar
Beartooth Regular
 
Join Date: Sep 2003
Location: Howard City Mi
Posts: 1,552
Now that you have a scale go to the next step, buy a powder measure and trust in your scale and measure. The dippers have long ago been proven to be very accurate and consistant with ball powders you may get a more accurate weight. Unfortunate thing we have to live with in our society is lawsuits, and making a powder dipper lawyer proof is very hard. If you want a dipper to be accurate make one out of a straight walled cartridge case. Weigh a charge put it in the case mark the case, remove the excess matierial just above the mark. Now weigh that case full, set your scale for that weight take ten weighed charges mark them down add them and divide by ten you will get the average of your dipper. Adjust until you have the dipper at the proper size, and accept the range you established by weighing and averaging. Above all trust the scale you bought. Use no other, and have fun with your new piece of equiptment.
Reply With Quote
  #6  
Old 03-17-2005, 05:45 PM
Banned
 
Join Date: Dec 2001
Location: Sandy, UT
Posts: 1,150
As above, Lee dippers seem to consistently throw charges as much as 5-8% light. I have never found one that throws heavy. This is most likely part of Lee's conservative approach. Also, technique governs consistency with a dipper. there is always the guy who doesn't have a scale, and wants "just a little more" and would use the dipper heaped up. Lee protects themselves by making it nearly impossible to throw a heavy charge, even when trying!

A set of check weights is just about as necesary to safety as the scale, they are not a luxury!

Finally, what you need to know first about the scale, even before accuracy, is how consistent are its readings. You don't need anything fancy to determine this, just any item within the range of the scale. Using the same item, weigh it several times. Thje weight should repeat precisely, no noticeble variation from reading to reading at all. If it does this, good. If not, return it or throw it away, it is absolutely worthless, and a hazard to your safety.
Reply With Quote
  #7  
Old 03-17-2005, 05:53 PM
Ranch Dog's Avatar
Beartooth Regular
 
Join Date: Oct 2003
Location: Cuero, TX
Posts: 3,484
Kart...

Your Lee Safety Scale is as accurate as they come. I went through the expense of buying a Lyman Check Weight Set (cost as much as the scale) and the Lee SS is right on the money each and every time at any weight. I can't say that for the other scales that I own or have owned.

You have to also understand that the Lee Powder Dippers measure volume and the density or weight of the powder that represents that volume can change from one lot of powder to the next. The differences that you are seeing is not uncommon from one lot of powder to the next. In fact the SAAMI spec allows it...

Powder cavity tolerances
"The powder manufacturers allow themselves a 16% tolerance in the density of their powder, from lot to lot. We have to calibrate our chart to show the high side of that tolerance, so you should never get more than what the chart indicates, but you will sometimes get less. Believe the scale. If your measure consistently throws less than what the chart indicates, try going up to the next larger cavity. If the powder measure throws more than what the chart indicates, please let us know!" (Lee Precision FAQ's)


Lee goes through a lot of effort tracking the Volume Measured Density (VMD) of every available powder and publishes updated figures on a regular basis (latest is 02/04/02). This VMD list is updated more frequently than the card that came with your kit (April 1995). Download the latest VMD Chart to use with your dippers. This also goes back to an earlier post of your's about the Lee Dippers vs. max allowable loads.
__________________
Michael

Last edited by Ranch Dog; 03-17-2005 at 06:00 PM.
Reply With Quote
  #8  
Old 03-17-2005, 08:28 PM
MikeG's Avatar
The Hog Whisperer (Administrator)
 
Join Date: Jan 2001
Posts: 26,495
Just out of curiousity, I weighted some change on my Dillon. It varies more than you think, so if you go this route, carefully mark the coins you intend to use before having them weighed, and don't lose them:

3 pennies, all 2001 or later (copper plated zinc core):

38.6 grains, 39.0 grains, 38.2 grains.

1 penny, 1975 (solid copper): 47.1 grains.

2 nickels, 1 1964, 1, 2000: 76.5 grains, 77.4 grains

Interesting....
__________________
MikeG

Quote:
Originally Posted by faucettb
Welcome to the forum. Rules are simple, be nice and join in.
Reply With Quote
  #9  
Old 03-21-2005, 11:29 AM
Registered User
 
Join Date: Jan 2005
Posts: 14
1 CC water = iMg there are conversions readily available to do the conversion. I use a syringe to measure the 1 cc. I, too, have a Lee scale and it is right on also.
Reply With Quote
  #10  
Old 03-21-2005, 02:15 PM
Beartooth Regular
 
Join Date: Oct 2004
Location: East Texas
Posts: 83
Kart29,
I had the exact same questions as you reguarding the accuracy of my saftey scale and about the dippers dipping differently than my scale. This week a friend got a saftey scale also, and they measured the same penny as the same weight. Good enough for me. Trust the scale.
Reply With Quote
  #11  
Old 03-21-2005, 02:48 PM
Registered User
 
Join Date: Mar 2005
Location: TN
Posts: 3
Lee Safety Scale

I used the Lee scale for over a year and found it to be very accurate. After a shelf fell on my loading bench I bought a weight check set to make sure my scales were OK. I found that they were still accurate in the lower range and in the heavier range (40 grains and up) they were .4 grains off. I replaced the Lee scale with an RCBS 505. www.midwayusa.com has a Lyman weight check set for $20.99, I would reccomend going ahead and getting a check set. The scale can easily become less accurate over time due to dust and dirt accumulation if you do not keep it covered.

If you have a lab in your area you may be able to talk them into weighing a couple of small items for you and make your own weight check set. Keep in mind that you need to clean the items well with alcohol or something that will not harm the item before having them weighed. Also on you have a weight check set, store bought or made, keep it stored in something to protect it and always handle it with tweezers to prevent dirt and grime build up.
Reply With Quote
  #12  
Old 03-21-2005, 08:18 PM
MikeG's Avatar
The Hog Whisperer (Administrator)
 
Join Date: Jan 2001
Posts: 26,495
Something to keep in mind is that no measuring device can be considered accurate, unless it can be calibrated against a known standard (and that standard is traceable to whatever agency keeps track of such things, these days).

Sometimes we just take things on faith, like the yardstick from the lumberyard being OK for what we need.

With a mechanical balance beam, if I could get it exactly zeroed when empty, and it weight say some 100 grain bullets within a grain (an average of maybe 10), I'd feel pretty good that it was within 1% or so. Since we all ought to be working up powder charges from below, that should do it. Powder lots will vary more than that, I can assure you!

With an electronic scale - use check weights. Anytime a computer is involved, best not trust it completely!!!!!!
__________________
MikeG

Quote:
Originally Posted by faucettb
Welcome to the forum. Rules are simple, be nice and join in.
Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Homemade Gas Checks ? jh45gun Handloading Procedures/Practices 19 06-05-2013 07:24 PM
Accuracy verses Precision Irv S General Discussion 19 02-19-2005 08:16 AM
Accuracy - rank the gun mods and reloading steps that result in improved accuracy flashhole Handloading Equipment 13 02-04-2005 03:38 PM
Lee Safety Scale... Ranch Dog Handloading Equipment 8 02-14-2004 07:30 PM
History Of The Gas Check John Kort Bullet Casting 3 08-29-2002 05:35 PM


All times are GMT -8. The time now is 10:12 AM.

< Contact Us - Shooters Forum - Archive >

 
 

All Content & Design Copyright © 1999-2002 Beartooth Bullets, All Rights Reserved
View Privacy Policy | Contact Webmaster | Legal Information
Website Design & Development By Exbabylon Internet Solutions
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.0 PL2