Lyman Scale Weight Check Set.

[MCMXI]

I recently bought a Lyman Scale Weight Check Set that comes in a nice little box with a pair of stainless steel tweezers and 10 weights.

Aluminum: 0.5gr, 1gr, 2gr (x2), 5gr
Stainless steel: 10gr, 20gr (x2), 50gr and 100gr

I was curious as to how accurate these weights are since I bought them to check my RCBS ChargeMaster and RCBS Powder Pro digital scales. I weighed each one twice on a Mettler XP504 (a $10,000 lab grade digital scale) and was very impressed with the results.

0.5gr > 0.0325g = 0.50gr
1gr > 0.0666g = 1.03gr
2gr > 0.1290g = 1.99gr
2gr > 0.1293g = 2.00gr
5gr > 0.3237g = 5.00gr
10gr > 0.6486g = 10.01gr
20gr > 1.2968g = 20.01gr
20gr > 1.2964g = 20.01gr
50gr > 3.2376g = 49.96gr
100gr > 6.4797g = 100.00gr

This set only costs about $35 so I wasn't expecting great accuracy but these check weights are more than accurate enough as can be seen by the actual weights in grains shown to two decimal places.

 

[rfwobbly]

Lyman is not a name that gets much center stage time these days, but they are without a doubt a first rate company with first-rate products.

 

[rg1]

Thanks for the info! Makes me feel more confident in my Lyman Check Weights.

 

[ReloaderFred]

I've had a set of the Lyman Check Weights for over 10 years, and they've proven very accurate when checked on expensive lab scales. They do good work at Lyman.

Hope this helps.

Fred

 

[MCMXI]

I didn't expect this .....

I've left the RCBS ChargeMaster on for months assuming that it would be more accurate if it was thermally stable ... well I was wrong. I calibrated the CM and weighed the check weights last night and the CM reported them all as between 0.1 to 0.2 grains UNDER the actual value. So I unplugged the CM and left it off over night. This afternoon I plugged it in, turned it on and weighed all the Lyman check weights again with much better results and I didn't even bother to calibrate the scale! A couple of them were reported as 0.1 grains under but the majority were right on. I guess I'll be unplugging the CM between uses from now and won't be bothering with the calibration routine. I'll just throw on the check weights for confirmation, then pile enough of them on the pan to get close the load that I'm dispensing e.g. the 50, 20, 1 and 0.5 to give 71.5gr if I'm dispensing 71.7gr. I'll do that at the start of the run and the end to see if any drift occurred.

 

[AgentAdam]

JFYI, Lyman = Pachmayr = TacStar = Trius = Uni-Dot = Butch's = A-Zoom = TargDots

 

[MCMXI]

The Lyman check weights have changed the way I reload!!

One of the issues with reloading using digital scales is drift error. As I mentioned before, I used to leave my RCBS ChargeMaster on constantly believing that it would be more accurate due to thermal stability. I found that this isn't the case for my scale. In fact, I don't even use the calibration feature since it's dead nuts on when I turn it on. This is how I reload now.

1. Turn on the CM.

2. Weigh each of the Lyman weights from lightest to heaviest i.e. 0.5gr, 1gr, 2gr, 5gr, 10gr, 20gr, 50gr and 100gr and record the values to 1 decimal place. None of my loads are over 75gr so there's no need to combine weights at this point to check the accuracy above 100gr.

3. Combine weights to give a weight as close to my load as possible. e.g. I made up some .223 loads on Friday using 24.5gr of IMR 4895 and a 77gr SMK HPBT bullet. I placed the 20gr, two of the 2gr and the 0.5gr weights on the pan and recorded the value (which the scale reported as 24.5gr)

4. Weigh out the loads.

5. At the end of the run (or sooner for a large number of loads), place all the weights (used in step 3) that are close to the load weight back on the pan to see if the scale has "drifted" and record that value.

6. Weigh each of the check weights again to see if the scale had "drifted" and record the values.


Weighing the check weights adds very little time to the process but the benefits to me are significant.


a. I can be sure that my loads are consistent from the first to the last in a loading session.

b. I can compare "apples to apples" e.g. a 24.5gr load from a month ago is the same as a 24.5gr load today which is important for load development.

c. My loads are independent of the scale or balance beam used.

d. From week to week, month to month or year to year, I can be sure that my loads are consistent regardless of atmospheric conditions.

e. If I buy a new scale or need to replace the one I have, regardless of which scale I use now or in the future, I can always adjust the load to account for any shift or error.

 

[ranger335v]

"Lyman is not a name that gets much center stage time these days, but they are without a doubt a first rate company with first-rate products."

If you mean from the various magazine hacks, that's always been true, at least for the last 50 years! Given the quality of Lyman's products I suspect they would get much better press if the "lent" the writers a lot of stuff, or "sold" it to them at great discounts like the more press popular tool makers do. Lyman just won't do that and I think I appreciate that from them. Infuence peddling bothers me, even when it's NOT done by congress.