I had been using a VIC-123 scale for a while now and this summer I up graded to a TD-153 scale. Well come to find out last night on a whim (should have done this when I got the scale) that there is a difference of 2 tenths between the two scales. With a check weight, with the scales set in grains, the VIC-123 weight was 1543.42 grains and the TD-153 was 1543.22 grains. That is enough to make a huge difference in my loads at 1000. No wonder I was thinking that my rifles were not shooting quite like they should be. So much so that I thought that my palma bbl had something seriously wrong with it. So with a match comming up in Nov in Chattanooga, I think that I will bump the load on the TD-153 for the .223 up to 24.2 which should equal what 24.0 would read on the VIC-123 scale. Though the lil gun shot well this past sunday in Memphis (599-39X) and it seemed that day it held good elevation, I was using heavy Lapua brass that day, but I still feel that a .2 difference in the load is enough to make a huge difference in the .223 and I know it would make a difference in my palma load.
A Difference In Scales
- Thread starter FroggyOne2
- Start date
Once I got my load I take a measured sample and store it away in a labelled vial and then use it as a check weight before loading again. My beam scale doesn't need to be checked as it's always dead on but the Acculab scale is the one that wants to drift and wander and needs extra care as mentioned by countless others.
It took me a while to figure out why champion long-range shooters that shoot little-bitty groups use old-fashioned beam scales till I got the Acculab123 Lol.
It took me a while to figure out why champion long-range shooters that shoot little-bitty groups use old-fashioned beam scales till I got the Acculab123 Lol.
This isn't an issue of drifting, it is an issue of the scales reading the same weight differently. There is a difference of .2 in the readout of the same weight between the two scales. So in order to make sure what load reading on the scale to use, I am going to have to go back and check the loads, but I am a betting man that on the TD-153, I am going to have to load 24.2 gr's of H4895 for the .223 and 46.7gr's of Varget for the .308. This is because the same weight read .2 lighter on the TD-153 vs. the VIC-123 that I had been using.
In my log book it shows 2 different weights (2/10th difference) for my 2 different scales for each load but sometimes I forget to check it. Unless we spend a grand on those lab scales there will be differences between them.
That's why I now use a check of the actual load before loading as a double-check on my brain and the scales.
I am not worried about the beam scale but the Acculab can crap out anytime and the beam gives piece of mind if I need to repeat a load if the 123 crashes.
Have you checked your 123 for repeating the same weight over different periods of time? You may be surprised.
That's why I now use a check of the actual load before loading as a double-check on my brain and the scales.
I am not worried about the beam scale but the Acculab can crap out anytime and the beam gives piece of mind if I need to repeat a load if the 123 crashes.
Have you checked your 123 for repeating the same weight over different periods of time? You may be surprised.
Thanks in2deep.effendude
Gold $$ Contributor
Just a thought here, but the scales reading .2 grains different with the check weight at ~1500 grains doesn't mean that you need to up all loads by .2 grains to correct it. I would weigh other items more near your powder weights on both scales and compare any difference. There most likely won't be any difference at all.
Think of this as shooting at 1000 yds verses 100 yards. A really accurate 100 yard rifle/shooter may be on the bottom of the list at 1000 yds simply because of slight, unnoticeable differences. Another way to think about is you have a difference in your standard of .2 grains over a 1543 grain measurement. Dividing .2 grains by 1543 grains gives a theoretical variation per grain measured of .00012962 grains difference between scales if it is a linear difference over the 1543 grain range. Does this make sense? Keep us posted.
Scott
Think of this as shooting at 1000 yds verses 100 yards. A really accurate 100 yard rifle/shooter may be on the bottom of the list at 1000 yds simply because of slight, unnoticeable differences. Another way to think about is you have a difference in your standard of .2 grains over a 1543 grain measurement. Dividing .2 grains by 1543 grains gives a theoretical variation per grain measured of .00012962 grains difference between scales if it is a linear difference over the 1543 grain range. Does this make sense? Keep us posted.
Scott
I like the vial idea too, but I wonder if I have space to store them.
FroggyOne2,
that .2 isn't really enough to make a difference in your load (certrainly shouldn't be, anyway), unless there's some basic problems with the load itself. This is the idea behind the ladder testing; to find those areas where a few tenths variance has minimal effect on the load and/or its accuracy. This will hold true for botht eh 223 and 308, though you'd naturally expect the 223 to be a bit more sensitive in this regard. Can't argue about the discrepancy betwen scales being troubling, either. It's not much, but this whole game is based on increments of "not much."
that .2 isn't really enough to make a difference in your load (certrainly shouldn't be, anyway), unless there's some basic problems with the load itself. This is the idea behind the ladder testing; to find those areas where a few tenths variance has minimal effect on the load and/or its accuracy. This will hold true for botht eh 223 and 308, though you'd naturally expect the 223 to be a bit more sensitive in this regard. Can't argue about the discrepancy betwen scales being troubling, either. It's not much, but this whole game is based on increments of "not much."
Effen,
Yeah, did a check, thanks for waking me up.. your right.. took a pan and zeroed out each scale, dumped a load of 24.10 grs of H4895 in the pan on one scale and the other weighed the same.. sometimes there was only a difference of .02 grains but as I moved the pan back and forth, it pretty much read the same thing. 24.1 or 24.08. So varience of weight is prob .02 grains, which is not enough to worry about.. I am glad that I started this thread, sometimes one does not think of the obvious when it is right in front of your nose.
Yeah, did a check, thanks for waking me up.. your right.. took a pan and zeroed out each scale, dumped a load of 24.10 grs of H4895 in the pan on one scale and the other weighed the same.. sometimes there was only a difference of .02 grains but as I moved the pan back and forth, it pretty much read the same thing. 24.1 or 24.08. So varience of weight is prob .02 grains, which is not enough to worry about.. I am glad that I started this thread, sometimes one does not think of the obvious when it is right in front of your nose.
Kevin,
When I get around to shootin the 90's again in the .223, .2 grains will make a huge difference in verticle dispersion, this is the reason that I was slightly freeking out about the scales.. but after having gone back and checked them as to how Effen said to try. I do feel better now and don't think that I have much to worry about.. Though, I do think that it would be good to put the scales on a slab of granite and get a line conditioner. One thing at a time.. right now I am looking for a place to get a inexpensive piece of granite to set them on.
When I get around to shootin the 90's again in the .223, .2 grains will make a huge difference in verticle dispersion, this is the reason that I was slightly freeking out about the scales.. but after having gone back and checked them as to how Effen said to try. I do feel better now and don't think that I have much to worry about.. Though, I do think that it would be good to put the scales on a slab of granite and get a line conditioner. One thing at a time.. right now I am looking for a place to get a inexpensive piece of granite to set them on.
effendude
Gold $$ Contributor
Froggy,
My wife has used granite pieces in some of her gardens for accents. Most of the granite shops/counter top businesses have scraps and broken pieces they simply throw away. Give a local shop a call, you should be able to find something pretty easily. BTW, I have Randy working on a couple of my rifles including a switch barrel 284 Shehane/.308 on a Barnard action so I'd appreciate it if you don't send him anything until he gets my stuff done.
Scott
My wife has used granite pieces in some of her gardens for accents. Most of the granite shops/counter top businesses have scraps and broken pieces they simply throw away. Give a local shop a call, you should be able to find something pretty easily. BTW, I have Randy working on a couple of my rifles including a switch barrel 284 Shehane/.308 on a Barnard action so I'd appreciate it if you don't send him anything until he gets my stuff done.
Scott
effendude
Gold $$ Contributor
Sorry Wayne,
I can't help you with that. I triple checked the match on my I-Phone, the office adding machine, and my daughters old Winnie the Pooh calculator and got the same .00012961762 although Winnie didn't take the decimals out that far. Your numbers are correct but the decimal point isn't. H
Have a great day everyone!
Scott
I can't help you with that. I triple checked the match on my I-Phone, the office adding machine, and my daughters old Winnie the Pooh calculator and got the same .00012961762 although Winnie didn't take the decimals out that far. Your numbers are correct but the decimal point isn't. H
Have a great day everyone!
Scott
Jay Christopherson
Not An Admin
Is that before or after both scales were calibrated with the same check weight? I've generally found that on initial calibration with a check weight, these scales *will* report the same weight... but some will quickly drift and the difference between your two scales doesn't seem unusual for a scale that has drifted. Drifting isn't a point in time thing- as a scale drifts, it will begin to report different (wrong) weights for the same weight. I think the difference you are seeing is drifting error and I would guess that if you ran the calibration process on both using your checkweight, they will (at least in the beginning) report the same weight.
FroggyOne2 said:
They were calibrated before using the check weight.
Scott, you better hurry.. I am waiting on the money for the one that I have sold now.. well really I will not start the build till prob around the end of Jan, that is usually when I send Randy my work.. usually a good time of the year to do so, Randy usually gets my stuff back to me in about a month or so.
Wayne, I was not trying to divide anything.. at least don't think so, I was saying that the numbers were off by .2, but going back and doing what Scott had suggested. It all came together.. so I am now not going to sweat it like I was earlier.
Scott, you better hurry.. I am waiting on the money for the one that I have sold now.. well really I will not start the build till prob around the end of Jan, that is usually when I send Randy my work.. usually a good time of the year to do so, Randy usually gets my stuff back to me in about a month or so.
Wayne, I was not trying to divide anything.. at least don't think so, I was saying that the numbers were off by .2, but going back and doing what Scott had suggested. It all came together.. so I am now not going to sweat it like I was earlier.
bozo699
Gold $$ Contributor
Well I figured out my math problem,....I think. A friend of mine read the thread and p.m'd me stating what he thought I had done wrong, I didn't think so,...but I tried again,...Nope same answer, 1.2961************ I spent at least a hour on it and new you were right, I finally got smart and grabbed another calculator, stabbed in the #'s and to my surprise the correct answer, turned on my cell phone and tried it's calculator,...correct answer again 
??? ??? I almost took a 28oz. hammer to my forehead then to the computer, the calculator on the laptop I am using WILL NOT!!! come up with the correct answer ??? Oh well I guess I am not as stupid as I thought I was, but my laptop's calculator is!! Thanks for not getting after me for being brain dead.
Wayne.
??? ??? I almost took a 28oz. hammer to my forehead then to the computer, the calculator on the laptop I am using WILL NOT!!! come up with the correct answer ??? Oh well I guess I am not as stupid as I thought I was, but my laptop's calculator is!! Thanks for not getting after me for being brain dead.Wayne.
Wayne,
Maybe you should have calibrated your calculators before hand,, or you might be incurring a drift factor that you were not aware of.
Maybe you should have calibrated your calculators before hand,, or you might be incurring a drift factor that you were not aware of.
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