Using dial calipers

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barnfrog

barnfrog

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Stopped at an LGS the other day to see if they had a couple things I've been looking for. They didn't, but while I was poking around I saw a used set of Lyman dial calipers. I've been using a pretty cheap set of digital, and the price was right so I bought them. They're not the quality of Starrette obviously, but I think they're an upgrade for me.

My question to those of you who use dial calipers is this: when you are taking a reading do you estimate tenths between the hash marks, or just round to the nearest whole/half? I seem to recall in junior high science class we were taught to estimate in between the marks, but even if that's true I'm not sure how much value there is in trying to estimate to the nearest 0.0001" instead of the nearest 0.0005". I can't adjust my dies to the nearest 0.0001" so what would be the point?

Curious what others do and what their reasoning is.
 
barnfrog said:
Stopped at an LGS the other day to see if they had a couple things I've been looking for. They didn't, but while I was poking around I saw a used set of Lyman dial calipers. I've been using a pretty cheap set of digital, and the price was right so I bought them. They're not the quality of Starrette obviously, but I think they're an upgrade for me.

My question to those of you who use dial calipers is this: when you are taking a reading do you estimate tenths between the hash marks, or just round to the nearest whole/half? I seem to recall in junior high science class we were taught to estimate in between the marks, but even if that's true I'm not sure how much value there is in trying to estimate to the nearest 0.0001" instead of the nearest 0.0005". I can't adjust my dies to the nearest 0.0001" so what would be the point?

Curious what others do and what their reasoning is.
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Round to the nearest value marked on the dial.
 
Just round up or down as you prefer. I say this as without calibration blocks

s-l1600.jpg

you don't have any idea how much your calipers are actually off. Nothing stays within calibration, everything wears, drifts, etc. Just because the dial reads to the millionth, or nano inch, don't take is seriously unless the caliper has been calibrated against a standard. By the way, these blocks, their dimensions change per room temperature.

I would say, round to the thousandth and which way you go, depends on whether you are a glass half full, or half empty sort of guy.
 
:cool:
Slamfire said:
Just round up or down as you prefer. I say this as without calibration blocks

View attachment 1094601

you don't have any idea how much your calipers are actually off. Nothing stays within calibration, everything wears, drifts, etc. Just because the dial reads to the millionth, or nano inch, don't take is seriously unless the caliper has been calibrated against a standard. By the way, these blocks, their dimensions change per room temperature.

I would say, round to the thousandth and which way you go, depends on whether you are a glass half full, or half empty sort of guy.
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lol. I’m a, “The glass is always full, only the proportions of liquid-to-gas will vary,” kinda guy. :rofl:
 
Lots of times the jaws of average calipers are not parallel to each other or have wear in the most used area of the jaws. There can easily be .001 difference from the tip of the jaws to the most inside part of the jaws. Measure the same part in different places up and down the jaws to check this. Along with temperature changes, cleanliness of the jaws and parts being measured and pressure by the user, means don’t try to split hairs with calipers. Not for reloading ammo anyway.
 

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Hartkopf said:
Lots of times the jaws of average calipers are not parallel to each other or have wear in the most used area of the jaws. There can easily be .001 difference from the tip of the jaws to the most inside part of the jaws. Measure the same part in different places up and down the jaws to check this. Along with temperature changes, cleanliness of the jaws and parts being measured and pressure by the user, means don’t try to split hairs with calipers. Not for reloading ammo anyway.
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When I started using calipers jaw flex was a real issue. They make ratchets on mic's for training wheels. I know of no such helper on calipers.
 
AJC1 said:
When I started using calipers jaw flex was a real issue. They make ratchets on mic's for training wheels. I know of no such helper on calipers.
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Most sets of dial calipers have a lock screw so you can lock in a measure and remove from the part to read. It can also be tensioned to help slow the action and make getting consistent measurements easier. Not exactly "training wheels" but when I was training newbies in the shops I'd use the lock screw to tension the action as a teaching aid. Worked pretty well with most people. Some folks just shouldn't have been allowed near a milling machine.
 
GeoDudeFlorida said:
View attachment 1094623
Most sets of dial calipers have a lock screw so you can lock in a measure and remove from the part to read. It can also be tensioned to help slow the action and make getting consistent measurements easier. Not exactly "training wheels" but when I was training newbies in the shops I'd use the lock screw to tension the action as a teaching aid. Worked pretty well with most people. Some folks just shouldn't have been allowed near a milling machine.
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Honestly it was me trying to make it say what I wanted not letting it tell me the fact of the matter... the gorilla grip doesn't seem beneficial with primers either...
 
243winxb said:
I estimate to the nearest 0.0001" on dial & mic. :(
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Well, at least you're man enough to admit it.

To be frank, it is tempting to try to estimate to the ten thousandth, but I think it would ultimately lead to frustration trying to get operations such as bullet seating or shoulder bump to repeat that precisely. I load hunting and plinking ammo. +/-0.0001" precision just isn't necessary for that.
 
Reading to within a tenth or two with calipers can be done but you have to understand all the variables, know your calipers and have a perfect touch. After all that, if the job is that critical, you should double check the reading with a mic. Of course if a person doesn’t understand all the variables with a micrometer, the readings can be way off too.

The biggest mistakes I see are too much pressure applied by the user, dirty jaws or parts, temperature of parts or tools at “wrong” levels and not calibrating or at least checking zero before measuring.
 
Soonerpesek said:
I know I am not as advanced as some of you, but I really don't see the need for measuring to the "tenths" in the reloading game.

Once again, I'm a minute-of-8"-gong at 100 yards or so, not a tiny hole group from a distant galaxy type of shooter...

.......IMO.........
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I don’t think it a “Need” but a “Want” people do things and think not all the same. I think if you Want .0001 tolerance - do it!

and I seriously think some reloaders would use a electron scan microscope if they had it.
 
First of all, how accurate do you NEED to be?

If your tolerances are to the hundredths or thousandths, then reading out to the ten-thousanths might be a bit insignificant.

It's also really easy to be a wee bit off with a set of calipers when taking measurements 4 decimal places or more. Minor changes on the angle the caliper is being applied will do it. How light or heavy a touch you have on the adjustment dial will do it.

You can practice technique, as well as do a "calibration check", by getting a set of feeler gauges and practice taking measurements of them with your caliper. Obviously feeler gauges won't work for larger measurements as a calibration check over a wide range, but are perfectly adequate for checking repeatability and accuracy of your measurement techniques.
 
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