Lyman M5 pointer graduations

[barnfrog]

Does anyone know if the graduations above and below the zero mark on a Lyman M5 beam scale are intended to indicate tenths of a grain, or are they just an uncalibrated reference? Neither the manual nor anything I've found online makes any mention of them. This is kind of long-winded, trying to anticipate the questions folks might ask, so if you don't want to read all the stuff I've done you can skip to the last paragraph.

I have a used M5 and have been cleaning and testing it to see if it is working correctly. Cleaned the knives and bearings with acetone and did some basic repeatability checks, and checked weights of different objects between the M5 and my cheap digital scale. Don't have a set of check weights yet, but will be getting a set in the near future. No shiny spots I can see on the knife edges.

After verifying the scale was zeroed, I moved the large poise to the 5 grain mark, and metered out 5 grains of powder (pointer at zero mark). Then I moved the large poise to zero and moved the small poise to its 5 grain mark. The pointer came to rest at the zero mark, so I then moved the small poise back to zero and the large poise to the 5 grain mark and again the pointer came to the zero mark so the small and large poise appear to be calibrated with each other.

Then I emptied the pan and put it back on the hanger, moved the large poise back to zero and the pointer came back to the zero mark, so it appears to be holding its zero.

So then I moved the small poise to the 0.5 grain position, but the pointer only moved 4 graduations. So either those marks aren't meant to indicate tenths of a grain, or the small poise isn't causing 0.5 grains worth of movement. I'm inclined to think the former, but wondered if anyone knew for sure. Not sure why I bothered to check that. I've noticed the newer scales don't have those graduations, just the larger marks above and below the zero mark.

Thanks for any help satisfying my curiosity.

 

[retfed]

Barnfrog, I have been using the Lyman 10-10 scale for about 45 years. The same base scale but they added a hard plastic cover, and the capacity is increase to measure up to double yours, by supplying a adding a 500 gr weight that you hang from the beam (has a loop for hanging.

Anyway, my observations are the same as yours on the graduations. They don't seem to correlate with movement of the weight. However, that being given, when adding powder, it's normally dribbled into the pan. when would you EVER add a KNOWN weight to the pan to bring the scale to the amount you are loading to.? Or if the pan load is over the amt you want, you either scrape some out or remove the pan and sprinkle some back into the powder bottle/cup you are working out of.

This seeming lack of coordination with the poise amt has never been an issue for me.

If you hear differently, please let me know.

Retfed

 

[barnfrog]

Barnfrog, I have been using the Lyman 10-10 scale for about 45 years. The same base scale but they added a hard plastic cover, and the capacity is increase to measure up to double yours, by supplying a adding a 500 gr weight that you hang from the beam (has a loop for hanging.

Anyway, my observations are the same as yours on the graduations. They don't seem to correlate with movement of the weight. However, that being given, when adding powder, it's normally dribbled into the pan. when would you EVER add a KNOWN weight to the pan to bring the scale to the amount you are loading to.? Or if the pan load is over the amt you want, you either scrape some out or remove the pan and sprinkle some back into the powder bottle/cup you are working out of.

This seeming lack of coordination with the poise amt has never been an issue for me.

If you hear differently, please let me know.

Retfed

Totally agree that you wouldn't use the graduations when weighing out a set amount of powder. But if you were weighing a bunch of bullets or brass to see what the variation was within a given lot, or to sort by weight as some of the more fastidious loaders do, they could be useful.

Anyway, it was mostly curiosity on my part, but I also thought that if the graduations were supposed to be tenths of a grain it could indicate the scale was off if they didn't match movements of the small poise.

Oh, and the M5 also has the extra 500 grain weight, so it will weigh amounts up to 1005 grains.

Thanks for the respose.

 

[barnfrog]

Besides, if they serve no purpose, why did they put them on the scale?

 

[JFrank]

I have several of those scales, those ive tuned myself and those ive had professional tuned.
Don't stress over the zero V groove as these old scales get a lot of use just zero /calibrate to your check weight.
I have attached instructions for scale set up. IIRC those are .1gr

 

[barnfrog]

Thank you, Jim. That is useful information.