Beam scale calibration

[Mr Underbridge]

I have a question about beam scale calibration. I am still tinkering with my M5 scale.
I have a set of check weights now and I was wondering instead of messing with the large weight and the smaller weight on the beam I could do something else.
I have check weights, could I just put down lets say my intedned weight of 43.5 grains and zero the scale on that and than weight the 43.5 grains?
I managed to balance the large weight but the the small weight is a bit off once you go past 0.5 grains.

 

[watercam]

Personally I use a 50 grain check weight to zero the scale. There is no guarantee that check weights are correct. I have a 10 grainer that is off .1 grain. As long as you are consistent in how you zero the scale, then work up loads with that zero you will be consistent with your measured charges. If it really bothers you Scott Parker does a nifty job of calibrating quality scales (ie not made in Mexico) and you might wish to have yours reworked. That or purchase lab grade scales which many folks do.
Many also enjoy the electronic dispensers. I use them for hunting and pistol loads and that's about it. When I check weighed charges from them on my beam scale there is variation. Since they do not weigh into the hundreds of a grain they have to round from .05 - .14 to achieve .1 on their scale. Not much to be sure but...
Here comes the barrage of comments!

 

[Webster]

I made my own standard out of sheet stainless at work. I sanded and weighed it on a lab scale until it weighed 32.92 grains (rounded from about five decimals). I call it 33.0 grains and I use it to zero my scale every setup. There is no reason to know if it's zero'd at 10 or 250 grains.

 

[wildfowler]

Here's how I calibrate my Scott Parker tuned scale every time I use it. I went over my procedure with Scott and he gave me his blessing as a good method.

I use a set of RCBS check weights. If I am measuring 47.5 grains of powder for particular load I initially set the scale to 45.0 and use 45.0 grains of check weights in the pan to zero the scale. Essentially I am only concerning myself with the exact position of the large weight on the balance beam.

According to Scott the biggest problem with an accurate readings is going to be as result of the positioning of the large weight in it's notch on the balance beam. So during my procedure with the check weight, if I see that the balance beam does not come to rest perfectly at zero I do not adjust the screw dial to physically raise the position of the beam. Rather I manipulate the large weight until it comes to rest in the exact position it needs to be to allow the beam to settle precisely at zero. This might involve me having to press the weight straight down to fully seat it in its notch, or simply moving it out of position and letting it settle back into position. Sometimes this might take a few attempts to get it to settle at zero correctly but it does eventually work every time.

I know my RCBS check weights are not scientific accurate but their mass does not change so they are capable of giving a consistent measurement as long as I keep them properly cleaned.

 

[BoydAllen]

What do you estimate the total error to be if you use the small weight in combination with the large weight to come to a setting that could have been achieved by using the large weight alone?

 

[chapstix97]

I have rcbs check weights. There are 2 twenty grain and 2 two grains. 1 ten grain is .1 lighter than the other ten grain same with the two grain 1 is lighter by .1 grain.

Got these weights 2 months ago, used tweezers handling weights