Digital Calipers...

[BCB]

I was trimming some 30-30 cases today and I was having an impossible time getting the Forster trimmer set to the proper length…

I finally settled on a setting that was close to what I wanted, yet I was still puzzled as to why I was getting variations in lengths…

After all 20 cartridges were trimmed, I began measuring and I discovered the problem. The bezel secure screw was lose and allowing the dial to not remain zeroed—phewwwwwwwww…

It is a Starrett and a fairly good set. It has worked well for many years. Tightening the screw solved the problem, but the calipers are getting old and a bit worn—yet still accurate I am sure…

My questions are: How accurate are the digital calipers and what might be a good brand? Are they as accurate as the mechanical calipers?

Thanks…BCB

[BCB]

Also, my Starrett has a step as most calipers do. What is the purpose of that?

What is the IP67 rating?...

I'm trying to move from mechanical to digital--although my age might make it a SCARY move!!!

Thanks...BCB

[tazman]

I have 2 sets of calipers. 1 mechanical, 1 digital. Neither is particularly expensive. Both read the same on test samples as my micrometer does.
The digital claims to be accurate to .0005. I doubt that is quite true but is certainly close enough for the purposes I use it for. The mechanical reads to even thousandths but can be eyeballed in between the marks. Again, that probably isn't particularly accurate but is good enough.
If I want really precise, I get out my micrometer.
The thing is, super precise measurement is seldom needed for my use.
I could spend a lot of time making the most precise ammunition possible and still would not be able to shoot up to it's capabilities. I do not have the physical capability to shoot match type accuracy.
My ammunition is as capable or better than any factory ammunition I have come across and for me, that is good enough.

[catskinner]

I quit using a digital calipers since the battery was often dead. Went back to using the Craftsman dial caliper I bought when I started reloading in 1976. Atill works.

[David2011]

I too find the battery life of the digitals aggravating. Jacketed bullets make a pretty good gage for testing the accuracy of calipers. Digitals display .0000 or .0005 so the accuracy is going to be +/- .00025; a full .0005 swing. That's more precise than we generally need. They're fast and convenient for measuring case length, OAL or verifying the diameter of bullets that have found their way out of the box. Most of the time I prefer mechanical calipers and find them to measure things the same as my good micrometers.

David

[Mauser48]

I have 2 pairs of mitutoyos. 1 pair is around 30 years old and still works great and its digital. The other pair is a dial pair. Digitals are just as accurate as long as you get a good pair. If I was getting a $15 pair at harbor freight I would get dials over digitals. Once you spend about $100 either one is just as accurate in my experience.

[country gent]

Digiital calipers can be very accurate, Feel, enviroment, and handling affect this. Some have an auto shut off ( a real pain in the butt at times). My mitoyos are 15 years old and on thier 4 set of batterys or so. Newer ones are much easier on the batteries also. For the utmostaccuracy measuring a set of gage blocks at the desired dimension first is a good idea. It then becomes a comparator. Most digitals can be zeroed any where along the scale so measuring 2.1" long cases, zero on 2" and .1 gage block stack then zero is 2.1 and + or - becomes .00X from zero. Starrett, Browne and Sharp, Mititouo, and othrs all make exceptionally accurate digital calipers. Dial calipers are good but fussy in dusty enviroments, and not always as easy to zero along the beam. Vernieers nd old eyes can be a real issue LOL.

[Ole Joe Clarke]

I recently bought a set of digital calipers for about 10 bucks. They are sufficient for reloading. I also have a set of Brown and Sharp slide calipers that I bought back in the 60's. They are just as accurate as they ever were, but my eyes seem to be out of tolerance, it's hard to see those tiny lines.

[daboone]

Being a visually oriented male I tend to look at the differences between digital and dial calipers as the difference between a girls numerical measurements and just looking at her curves. It is instantly easier to see the differences than interpret the numbers but the numbers are still available. Never understood why some guys need batteries to get the job done.

[jmort]

I have both kinds, but got this electronic model for $28.99 and really like it

http://www.amazon.com/dp/B003119EDE/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=27UO44IFJYUFC&coliid=I2TFTQKZWP78E2

[seagiant]

Hi,
I prefer dial calipers.

Mitutoyos can be bought used on the Bay for a decent price!

[bedbugbilly]

I have a set of battery digital calipers that I bought from a member here a couple of years ago - I'm sure foreign made - he had a bunch of new ones and I picked up two for around $20 a set or so. I love them.

I'm "old" and was trained many years ago in machining (I taught shop a few years) and all we had were dial calipers and standard micrometers. So . . I'm "old school". But, I have had eye problems over the years (diabetes) so my vision is not that of a 20 year old (plus I'm over 3 X that age now anyways - LOL). I find that they work well and are plenty accurate for my uses. But, when checking a "barrel slug" - i.e. slugging the barrel, etc.) I will pull out my micrometer that I've had for 40 + years. I'm surprised at how many times I reach for my dial calipers though - I use them quite a bit so they are always within easy reach.

[mdi]

As a life long machinist/mechanic I've used calipers in many situations from measuring length of 2-56 screws to crank journals on a Cat 400 engine. I have had at least two different digital calipers, (one bought off the Snap-On truck) and after a bit of use, like 3/4 hr. found I could not trust them. One caliper would auto shut down way too soon/often and one jumped between metric and SAE by itself. Not caring for replacing the batteries either when I needed the tool. I was always doubtful/uncomfortable with some numbers just appearing on a read out (seemingly random). I went back to a decent dial caliper (the one I have now is Craftsman, but owned a very good Starret, since stolen). I have had the set I'm using now for 10-12 years and have not had to replace anything, tweek anything, just pick it up, check zero and measure...

[ole 5 hole group]

I use a digital Starret - they are rather expensive ($165) compared to most other calipers on the market but I have found them to be spot-on every time I've checked them against a micrometer. I maybe use mine on 6 or 8 occasions a month and my battery will last close to 18 months. I have the automatic shutoff feature but it takes awhile, so I normally just manually shut it off after use.

I don't think anyone needs a caliper that expensive in their reloading room - I have one just cause and I fully expect that Starret to be around functioning perfectly for my grandkids well after I'm gone.

[dkf]

Also, my Starrett has a step as most calipers do. What is the purpose of that?

What is the IP67 rating?...

I'm trying to move from mechanical to digital--although my age might make it a SCARY move!!!

Thanks...BCB

The IP67 rating is for water (coolant in a machine shop) and dirt/dust resistance. Some reading http://resourcesupplyllc.com/PDFs/WhatDoesIP67Mean.pdf

Only calipers I buy anymore is the electronic Mitutoyo Coolant Proof IP67 Absolute calipers. I just wish they would make a 24" or at least an 18". They are just accurate if not more than a dial or vernier. I have some regular non coolant proof Mitutoyo calipers too and I like the auto off feature on the IP67 calipers, saves me a lot of batteries over the life of the caliper. They are not the cheapest but they take a beating.

Some of the companies like Starrett are putting out some imported junk theses days. My dad bought a Starrett electronic 6" on sale from MSC for around $100 and it was foreign ****.(he sent it back and told Starrett what he thought of it) The feel and fit was **** so buyer beware.

That said for reloading you don't have to spend a lot unless you want to. Quality tools are just overall nicer to use. Just remember even with a high quality caliper, it does not replace a micrometer when accuracy is needed.

[hpdrifter]

I've had 2 digitals fail me and 1 dial; two being starret and one ??????

I went back to my verniers. They haven't failed in 30+ years. just need a magnifing glass with em now.

[rtracy2001]

I quit using a digital calipers since the battery was often dead.

I have a HF digital caliper and seems quite accurate (comparing to my micrometer calibration checks). The feel isn't as good as the "quality" brands, but I wanted an easy to read beater for the everyday tasks. I don't have a machine shop.

The battery life problem was easy to solve: Remove the battery before putting it in its case. I went from 5 weeks battery life to more than 5 years. Your mileage may vary.

[Boolit_Head]

I've had a dial caliper that has served me well for 20 years. But lately I was noticing some inconsistent results measuring bullets. Not off by much but difference each time i measured the same bullet. Checked the zero everything. Bought a Enco Mic off Ebay for 9 bucks and that thing is dead nuts repeatable every time to at least 3 places. 4 places of I am sure to apply the same amount of pressure. I like it so much I am getting a 1-2 inch version to measure case lengths and oal.

[cajun shooter]

After going to trade school for two years in the 60's and then dropping out for military service I can say that I love my digital calipers but if I need an exact, I reach for the mike.
I have one set of standard calipers by Dillon and they seem to be very well made and I 've used them for many years. I also have a set of digital calipers made by Starrett. Buy the best you can when it comes to these type of tools. The $12.95 version is at it's best when using the 1 inch scale.

[trapper9260]

Hi,
I prefer dial calipers.

Mitutoyos can be bought used on the Bay for a decent price!

I do also like my dial ,They are RCBS make and when I was in the shipyard building subs I use them there and had them check with QC back then and they where good enough for ship building beside reloading.I got my back in the mid 80's.

[jmorris]

The digital claims to be accurate to .0005.

Digitals have a resolution to half a thousandth but there is a difference between resolution and accuracy.

Not that it really matters for case length but if you want accuracy to a half a thousandth (or better) a caliper is not the right tool. A micrometer is a much better choice.

[williamwaco]

I am amazed at the reports of how accurate the calipers are!

I have 4. 2 dial and 2 digital. None were expensive. $50 or less.

I chose a Mitutoyo mike. Something over 200. (Digital) Eats batteries for breakfast.

On measurements in the sub one inch range, none of the calipers measure the same and off from the mike by 0.0005 to 0.0015.

I use them for case length and OAL, and identifying unknown bullet calibers but nothing else.

Oh yes, I have a vernier I bought around 1958. Haven't used it in 30 years.

[ole 5 hole group]

I am amazed at the reports of how accurate the calipers are!

I have 4. 2 dial and 2 digital. None were expensive. $50 or less.

I chose a Mitutoyo mike. Something over 200. (Digital) Eats batteries for breakfast.

On measurements in the sub one inch range, none of the calipers measure the same and off from the mike by 0.0005 to 0.0015.

I use them for case length and OAL, and identifying unknown bullet calibers but nothing else.

Oh yes, I have a vernier I bought around 1958. Haven't used it in 30 years.

You sound like a hard man to please in the reloading room - off by 0.0005" is probably close enough for government work!!;-)

[DougGuy]

I have a Starret plain old vernier style with no readout that when I have my clip on readers in place, I can still read them and they work but only to the nearest .001" and are a pitb for these old eyes. I used them for 30yrs before I ever got a set with a readout. I fall back on them every now and then.

I have a Mitutoyo dial set that I bought used and always seem to be in question of whether it's right or not.

The digital set I use most is a Kobalt set from Lowe's that I can take and trade in whenever they start acting odd and they are about as accurate as you would need a caliper to be.

One day I will have a nice Mitutoyo digital and I can go trade the Kobalt in for some Asian made LED light bulbs or some other typically questionable product at the big box store..

Edit: NONE of these can be used on cylinders and slugs. Calipers will only get you close and more times than not will be giving the wrong reading. Pin gages and a decent mic that reads in .0001" are the only acceptable tools to be using for throats, sample boolits and slugs. Unless you have an air gage..

[ole 5 hole group]

Edit: NONE of these can be used on cylinders and slugs. Calipers will only get you close and more times than not will be giving the wrong reading. Pin gages and a decent mic that reads in .0001" are the only acceptable tools to be using for throats, sample boolits and slugs. Unless you have an air gage..

Agree, but I find they will get you close enough to guess what it probably is - I had to purchase a pin gauge set and only use a few of the pins and had to purchase several individual pins in the 0.510 range for the Linebaughs, as most sets top off at 0.500" unless you want to start-off on the large size - Like the monkey said when peeing in the cash register - this all runs into money.

[jmorris]

On measurements in the sub one inch range, none of the calipers measure the same and off from the mike by 0.0005 to 0.0015.


It might help if you keep standards handy so you can get the "feel" for measuring correctly with the calipers; however, as I said above half a thousandth is the resolution of digital calipers not the accuracy. If you want to be that precise stick with the micrometers and forget about the calipers.

http://i664.photobucket.com/albums/vv5/qvideo/IMG_20150104_133015_996-1_zpsbabb46c4.jpg