Beam Scale Accuracy

[sparker]

I was very recently asked about the accuracy of my scales. I warranty them to be plus or minus 1/20th of a grain from true value unless otherwise specified. Many however are considerably tighter than this. Note the scale pictured below. It is set to read at 493.8 grains with 32.000 grams or 493.824 grains in the pan.

 

[sksshooter]

Scott, on the m5 as you have pictured. the scale on the indicator side with zero being the middle what is the value for each line above/below the zero mark? the main beam scale is in 5's, the right side is in tenths. i've made an assumption those are hundredths but is that a wrong assumption?

 

[BoydAllen]

Scott, on the m5 as you have pictured. the scale on the indicator side with zero being the middle what is the value for each line above/below the zero mark? the main beam scale is in 5's, the right side is in tenths. i've made an assumption those are hundredths but is that a wrong assumption?

The smallest increments on the RH side are tenths.

 

[sksshooter]

The smallest increments on the RH side are tenths.

Yes thats what i posted above?

 

[Zero333]

I bought a set of check weights for reloading scales about 12 years ago.

The set (RCBS or Lyman,.. can't remember anymore) comes with.. 0.5 gr, 1.0 gr, 2.0 gr, 5.0 gr, 10 gr and 20 gr precision weights to make sure any scale used for reloading is on the money.

Once you have a set of those weights you will never wonder weather your scale is bang on the money or if it's deceiving you.

I use a RCBS Chargemaster 1500 dispenser, but I still have a RCBS 505 scale that I used the check weights on before every loading session and it was always on the money.

 

[sparker]

There’s a reason I use NIST traceable calibration masses.

 

[sparker]

The high level of accuracy shown above, near full scale value, is indicative of the quality of the M5 scales. When someone asks me what the best is, I tell them an M5 all things considered. If I only got to have one scale, an M5 would be it. With a D5 as a close 2nd. I use an old, old Redding currently as I only load for rifle.

 

[Murray Brook]

@sparker
As was asked before what are the values on the zero scale in the left of your picture ( at the end of the beam pointer) of the M5. TKS

 

[JFrank]

IIRC those are 1/10 grain increments.

 

[sparker]

@sparker
As was asked before what are the values on the zero scale in the left of your picture ( at the end of the beam pointer) of the M5. TKS

The marks directly above and below the zero line are approximately 1/10th of a grain. As the beam indicates further from zero, the marks grow in value.

 

[Murray Brook]

Thank you

 

[Bc'z]

@sparker
As was asked before what are the values on the zero scale in the left of your picture ( at the end of the beam pointer) of the M5. TKS

Roughly 6 kernels of N140

 

[sparker]

Yes

 

[DLT]

For what it’s worth my old 502 scale will detect 1 kernel of varget. Can I shoot the difference ? Probably not, does it make a difference ? I highly doubt it

 

[PhilC]

For what it’s worth my old 502 scale will detect 1 kernel of varget. Can I shoot the difference ? Probably not, does it make a difference ? I highly doubt it

Agree and know I cannot shoot the difference.

 

[K22]

My M5 is over 50+ years old and currently out of service due to the knife edges being worn to the point that the balance does not return to zero. When in service, I routinely checked with calibration weights and the balance was consistently within the mfg.'s stated accuracy limits of + or - .0.1 grains.

About 3 years ago or so I purchased a Lyman Brass Smith beam balance as a stop gap measure, that also has a claimed accuracy of + or - 0.1 grains. With check weights, I found that to be so throughout the powder charges I use, i.e., pistol, 5.7 to rifle, 40.0. I had some difficulty maintaining a zero but with the help of Boyd Allen I corrected that problem.

In my experience, ball powders are much more sensitive to changes in powder charges than extruded powders. The ball powders seem to have a smaller window whereas the extruded powders are more forgiving. Of course, the ball powders meter much more precisely than extruded powders.

Several years ago, I ran some tests with 223 Rem case capacities purposely varying the powders charges 0.2 grain with IMR 4895, representing the mfg.'s stated accuracy of the M5, i.e., -.1 to +.1. While this was not done under laboratory conditions or commonly accepted statistical sample size of 30, I could not detect any difference on target with varmint grade accuracy rifles i.e., 1/2 to 5/8 moa.

 

[Tesoro]

I am a huge M5 fan. I like the needle addition.

 

[Doom]

I don't own a beam scale but have used several over a collage and work career that spans a period of 54 years. Early in my work career electronic scales were coming out and we were skeptical of there accuracy and repeatability. Drift was a huge problem but it turned out we simply needed needed to check/zero the scale before each weighing. Kinda like you would do with a beam scale.

So 50 years later we still argue about which is better or more appropriate. But there is one constant over that period, a quality scale is a quality scale and a piece of garbage is …

 

[sksshooter]

I don't own a beam scale but have used several over a collage and work career that spans a period of 54 years. Early in my work career electronic scales were coming out and we were skeptical of there accuracy and repeatability. Drift was a huge problem but it turned out we simply needed needed to check/zero the scale before each weighing. Kinda like you would do with a beam scale.

So 50 years later we still argue about which is better or more appropriate. But there is one constant over that period, a quality scale is a quality scale and a piece of garbage is …

i didn't see where anyone was arguing one was better than the other at least in this thread. in general yes i agree folks do still argue it quite frequently. i personally don't believe one is less capable than the other. i do however believe it costs a lot more to have a quality digital scale over a quality beam scale. the only digital scale i have is a cheapy that mainly gets used just for quick weighting of unknow weighted bullets etc. I'm honestly amazed how accurate it is for a $20is scale but every single check weight I've put on it has been spot on. will i ever purchase a decent digital scale and trickler? maybe so but it doesn't fit my needs at this time. although the number of beam scales i have/had would have well paid for a fx120 and auto trickler. the bulk of my larger rifle loading happens while working up a new load. once that is done i load up 20-30 rounds and that lasts me a couple years. i do like to shoot a group from my hunting rifles once a year to make sure they are holding zero but i just don't shoot enough to warrant a digital setup at this time. my pistol and 223 ammo are all thrown loads.

 

[JFrank]

I loved my beam scales but sadly I had to make a change.
Once a change has been made I rarely look back.