Caliper or Micrometer?

[DavZee]

Is one better then the other for gun related measuring? I'm looking for a new measuring devise. I have the Harbor Freight digital caliper but it's my second one and I don't trust it's accuracy. It sometimes gets fluky and I have to turn it on and off several times to get it to settle down. I want to get a mechanical tool. No batteries, always works, always accurate. But which on is best? Do I need to spend a lot?

[40Super]

A mic is always going to be more accurate but you would need 2 or three at least to cover the average range(0-1in,1-2in,and2-3in).
A GOOD quality caliper will be accurate enough for most situations in reloading,as long as care is taken with the amount of pressure applied when measuring. I have a Brown and Sharp and a Mitutoyo digital(batteries)for work and they have no problems with being reliable,so I wouldn't count out a battery powered unit,as long as it is a GOOD quality one.

[engineer401]

I have a RCBS dial caliper. and a vernier Mitutoyo micrometer. Batteries don't die or leak. I am very happy with them. The micrometer is more precise and more expensive. I use the the caliper most of the time as it faster.

[eniku40]

You need one of each (my Harbor freight one is doing fine - for now). Check out Amazon for a micrometer that costs around $15 - it is pretty decent at 0.0001 inch.. (vernier micrometer).

Basically, micrometers for diameters and calipers for length/depth measurements.

If you can have only one, get a caliper. Micrometers don't get past 1 inch without heading north on prices, and in a pinch you can use the calipers to get a close enough measurement.

Just understand that at the limit of their resolutions, both devices will waver a little. (and this has more to do with the pressure you apply than with the device itself).

If you really (really) need an accurate measurement, take 5 measurements, drop the highest and lowest and then take the average of the remaining 3.

[462]

Measure boolit diameters and bore slugs with a micrometer. Calipers will work for measuring cartridge overall length.

[adrians]

Measure boolit diameters and bore slugs with a micrometer. Calipers will work for measuring cartridge overall length.

yup ,
both instruments are needed ,in my meager opinion .
my "weapons " of choice are starretts but there are a few good makers out there, i prefer the " Made In usa " stuff.

:evil: :bigsmyl2: :evil:

[Kevin Rohrer]

I have a vernier caliper and use it alot. I'd like to get a ball micrometer for measuring case head expansion, but they are pricey. The caliper works almost as well.

[Ziptar]

Two different tools two different jobs. You'll need both.
0-1" Micrometer to measure bullets, bore slug, and case diameter.
Calipers to measure empty sized cases and loaded rounds lengths.

I was able to buy a micrometer and a dial caliper (both made by Brown & Sharpe) second hand for less than $20 each with the shipping on eBay.

[3006guns]

I do my own machine work and noticed that something that hasn't been mentioned....calibration.

Both micrometers and dial calipers should be checked periodically for accuracy. Usually a "standard" is used for this and consists of a simple, straight and expensive rod of steel that is a PRECISE length. Both the rod and the micrometer should be the same room temperature when checking. If the mike is off slightly it can be adjusted to agree with the standard.

O.K....having said that, use a ball bearing of a known size for a standard. They are ground very accurately and will serve the purpose very well for a heck of a lot less money!

[RayinNH]

If you want two, buy two. Toys are always good.

My son works in a machine shop. One day he saw a micrometer in the trash barrel and pulled it out. It had a very tiny burr on the anvil. He carefully stoned it off and checked it against a standard. It was right on. He offered it to me for reloading purposes. I used it a couple times and gave it back to him. The tiny little lines gave me fits trying to read.

I've used my Mitutoyo for 30 years now. Plenty accurate for reloading purposes...Ray

[largom]

As everyone has stated, you need both. You also need a standard. In my shop I have micrometers that range up to 6 in., also have top quality dial calipers. In my loading room I have a 0 to 1 micrometer with carbide tips, also a ball micrometer. My most used tool for loading is a Harbor Freight vernier [I have 4 ]. At a price of 10-15 dollars each it's no big loss if one falls off the bench on the concrete floor. I check these Harbor Freight verniers constantly with my standard and they have always been very accurate. Usually when one starts to flutter it means the battery is weak and needs replaced. Batteries are available at Walmart for about $5.00 for pack of three. The battery is a #57 and usually last several months if you turn the vernier OFF when not using.

Larry

[Longwood]

I bought a NEW pair of calipers from China on ebay.
I paid a little over $8 shipped.
No nonsense such as taxes.
They are the exact same caliper that Home depot sold me for over $40 after the governors cut.
However, I did not get a fancy case but it just so happens I have another case from a Mitutoyo that I dropped which destroyed it immediately.

[Longwood]

Batteries are available at Walmart for about $5.00 for pack of three. The battery is a #57 and usually last several months if you turn the vernier OFF when not using.

Larry

I shop where Walmart shops.
China!
Why buy the exact same things after Walmart marks them up several hundred persent?

We can buy G13 batteries for around $5 a hundred I buy the Alkalines which are sooooo much better.

[largom]

I shop where Walmart shops.
China!
Why buy the exact same things after Walmart marks them up several hundred persent?

We can buy G13 batteries for around $5 a hundred I buy the Alkalines which are sooooo much better.

Tell me where to buy them! Thanks ahead of time.

Larry

[rasto]

Largom try an ordinary Ebay, just put the type which are you looking for.
If I were you, I would prefer silver oxide type against alkaline but the price is somewhere else.
I have caliper and micrometer from china as well and using it with pleasure.

[Longwood]

I do my own machine work and noticed that something that hasn't been mentioned....calibration.

Both micrometers and dial calipers should be checked periodically for accuracy. Usually a "standard" is used for this and consists of a simple, straight and expensive rod of steel that is a PRECISE length. Both the rod and the micrometer should be the same room temperature when checking. If the mike is off slightly it can be adjusted to agree with the standard.

O.K....having said that, use a ball bearing of a known size for a standard. They are ground very accurately and will serve the purpose very well for a heck of a lot less money!

1" mike.
Check zero when the anvils touch.
Check with the standard at 1".
Checking with a ball bearing would only check it at one spot.
Calipers are all made about the same. Micrometers are another story. Cheap ones don't come with a standard for good reason.
A cheap Harbor Freight Mike is internally different than a quality mike and can vary too much, probably about as accurate as a caliper.
Once you learn to use a caliper properly. the caliper wiil be close enough unless you are making precise parts.
By precise, I mean plus or minus .0001 not .001.

[Longwood]

[QUOTE=3006guns;1569668

Both micrometers and dial calipers should be checked periodically for accuracy. Usually a "standard" is used for this and consists of a simple, straight and expensive rod of steel that is a PRECISE length.

So people undersand a little better how accurate quality Micrometters are.
The "standard" mentioned here, is a piece of 1/4" diameter tool steel ground to "EXACTLY" 1" in a temperature controlled room. They have a thick plastic sleeve molded around them so your body temperature will not effect the length while you are handling them.
How much could my body temp effect a 1/4" rod 1" long?
Enough to be way too much for a good machinest.

[Reload3006]

You should also check for parallelism and flatness of your anvils from time to time with optical flats you can do the same thing with a small precise ball measure the ball several times in different places on the anvil is should all read the same if it does not your anvil spindle are not in alignment and must be lapped in. or replaced.

[RayinNH]

Once you learn to use a caliper properly. the caliper wiil be close enough unless you are making precise parts.
By precise, I mean plus or minus .0001 not .001.

Bingo. Calipers are plenty accurate for the reloading process. No need to measure to the nearest .00025" and then jam a slug that is .002-.003" oversize down the barrel...Ray

[theperfessor]

If you look at Enco or MSC they often have machinist's starter sets, usually w/a 6" caliper of some type, a 0-1" outside micrometer, a 6" pocket scale, and a case. If you know you're going to buy them all anyway why not get a set at a lower price?

[Longwood]

If you look at Enco or MSC they often have machinist's starter sets, usually w/a 6" caliper of some type, a 0-1" outside micrometer, a 6" pocket scale, and a case. If you know you're going to buy them all anyway why not get a set at a lower price?

Hi Perfessor.
Are you the guy that showed me the photo's of a 'J' drill for Paper Patch mold making?

[40Super]

Most Starret,Mitituyo,or Brown & Sharpe mics will come with their own check gage,so it isn't an extra expense.
The parallelizm of the anvils on calipers is where the cheaper ones won't compare with the good ones,plus they will flex more.

[Houndog]

What Perfesser said +1
I'll go a little further and suggest you buy a Starret, Mitutoyo or Brown and Sharp starter set! Cry once when you buy quality and smile every time you use it or buy cheap and cry every time you use it.

FWIW: I use Mitutoyo because their graduations are larger and better defined. They just suit my old eyes better..

[DavZee]

Thank You all for taking the time to respond. All the comments were helpful. I think I'll be going with a mechanical Caliper/micrometer set. I need to have both any way. I did replace the battery in my Harbor Freight caliper and it seems to be working better.

[theperfessor]

Longwood -

Don't recall doing what you refer to, I've never posted anything about the topic you mention.

[captaint]

Dav - Sounds like you're on the right track. Mitutoyo stuff is quite decent. Someone is now making ball mic's at a reasonable cost - for measuring case neck thickness. They can come in handy.. enjoy Mike

[40Super]

I know Craftsman did offer some mics and calipers,they were acually made by Starret,so they arwe of decent quality.Back in '89 when I started tech school I needed some mics and other stuff for class,I was extremely limited in funds so I bought 2 Craftsman mics and a dial caliper,the mics were well made and accurate on both ends of their range.Well fast forward,when I got a job and eventually started buying all the other measuring tools needed for machining,I then bought Starret and Mitituyo for debth mic set,the other sizes up to six od mics ect..It ended up a couple years I used the Craftsman full time till I got everything else I needed.Not once did I have to adjust them,always accurate.I did then replace them with Brown and Sharpe for at work,but I still use them at home,still good.

[superscifi12]

1" mike.
Check zero when the anvils touch.
Check with the standard at 1".
Checking with a ball bearing would only check it at one spot.
Calipers are all made about the same. Micrometers are another story. Cheap ones don't come with a standard for good reason.
A cheap Harbor Freight Mike is internally different than a quality mike and can vary too much, probably about as accurate as a caliper.
Once you learn to use a caliper properly. the caliper wiil be close enough unless you are making precise parts.
By precise, I mean plus or minus .0001 not .001.



Not to pick BUT if a mic zeros and measures a 1.000" part doesn't mean it will read good anywhere else as those are the two least used areas on the mic (in terms of measurement range). Better would be to get 2 or 3 ball barring of known size and use them.

Calipers are NOT all made the same. I've used the $10 Chinese specials and the $120 Brown & Sharpe. Repeatably, accuracy and comfort are top differences. (guess which one my box has in it? and how many?)

My $150 Starrett Mic didn't come with a standard. Starretts don't come with standards anymore. So high end mics (except for B&S) don't come with standards, you can buy them for $20-$50. Buy a name brand and get the best you can. Look up the other thread on mics for more info.

I work at a precision machine shop. Industry standard is to use a measuring tool that can measure 10x better then your looking for. IE if you want .001 than you need a tool that can read .0001 or if you want .01 than use one that can read .001. So a caliper is only good for reading .01 or more in tolerance.

[Reload3006]

I pretty much agree with Superscifi12 I too work in the machining industry and now am working in a calibration lab. However The accuracy ration is 4:1 not 10:1 ISO 9000 But it really doesn't matter. If you buy a micrometer with a digital readout or a vernier scale so you can measure .0001 I can tell you that you will not measure accurately to .0001 just will not happen. Unless you have a micrometer that eliminates operator feel. Yep I said feel and if you think that the friction thimble or ratchet stop will allow you to measure accurately to .0001 Sorry it will not. In fact to measure repeatably to .00005 Fifty Millionths you have to be in a controlled environment and using a super mike. Its not something you can hold in your hand. To get repeatable .0001 measurements you need to be in a controlled environment. using tools like snap gauges or indicator anvil micrometers. Just because you have a digital micrometer (mititoyo makes one) that reads to fifty millionths does not mean you can use it to to definatively say something is thus sized to within +/- .00005
All that said to say buy a mike with a friction thimble or a ratchet stop with a ten-thousandth vernier scale or digital and you will be accurate enough for any thing you will ever need to do in the casting swaging reloading world.

[geargnasher]

Cheap dial-indicator calipers and an expensive 0-1" micrometer with ten-thousandths vernier on the thimble is all you need. Find a local machinest, offer to buy him lunch at a decent restaurant one day if he'll show you how to "feel" measurements with a thimble mic. Take a pocketfull of non-toxic items like J-word bullets, clean sized and unsized cases (measure the empty necks!), etc. with you. A good machinest can "teach you to fish" for a lifetime in a few minutes with good tools.

Gear

[1hole]

Every time the question of what's good for measuring reloading stuff comes up the helpful professional machinests lay B&S, Starrett and Mitutoyo on some poor guy just trying to do better work on his ammo. Fact is, the 'cheap-o' Chinese micrometers and calipers are astonishingly good and a bargain for anyone not making his living using the tools ever day for decades.

I do have a very precise 1" B&S micrometer reading in tenths and a Swiss made vernier caliper that's easily accurate to a thousant across it's 6" range. I also have three Chinese mics in an inexpensive set with full range test blocks of 1", 2" and 3", two Chinese 6" dial calipers, one 6" digital caliper and one 12" Chinese dial caliper in my shop. As checked on my Jo blocks, they are virtually as 'accurate' as my high cost pro-grade tools,

Thing is, if I drop any of them on a concrete floor they are shot no matter how much they cost but I can buy some 10-15 Chink replacement tools for the cost of a single B&S, Starrett, etc. The economics of that has driven a LOT of small proffesional machine shops to stock Chinese/Harbor Freight stuff for all but the most demanding work. SO - I have my good stuff carefully locked up in the shop but I'm quite happy to use Harbor Freight stuff in my reloading room - and for most of my machine work too.

[geargnasher]

Here's the thing, 1Hole, you know how to USE cheap measuring tools, and have the calibration tools to check them with. If I have nothing, and buy a HF odometer-style 0-1" 'micrometer', I still don't have any guarantee of good accuracy more than a decent set of dial calipers. Maybe I'm too OCD, and have like you an array of top quality tools as well as cheapos, but for me the cheapo stuff goes in the wood shop where I won't cry if it gets dusty or rusty and the good stuff is for engines, transmissions, and guns.

Gear

[1hole]

"...the calibration tools to check them with. If I have nothing, and buy a HF odometer-style 0-1" 'micrometer', I still don't have any guarantee of good accuracy more than a decent set of dial calipers. "

Mics are best used for measuring bullets and case head expansion while calipers are for case length and OAL; none of that is highly demanding. Bullets are usually a comparitive thing, bore-to-bullet diameter, and a couple thou off a length measurement is meaningless anyway.

I love 'nice' tools but not everyone needs them; all of my inexpensive Chinese tools are much more than sufficently accurate for reloading. That seems to match the judgement of our reloading companies too, it appears that all who sell house branded calipers are getting them from the same Chinese maker as Harbor Freight (but the prices are marked much higher). Thing is, nothing about reloading requires really high accuracy measurements and a common set of auto mechanic's feeler gages, or even a good bullet, will provide pretty good test "blocks". Those who don't know how to use a mic reading in tenths won't be able to do so no matter how expensive his mic is!

Bottom line, my cheap-o gages do quite well at very low cost and no reloader is going to 'wear out' any such devices in normal use. Thus, I hate to see suggestions for high quality gages that are priced out of the justifiable reach of casual reloaders who would gain nothing even if they did buy the professional grade tools!

[Reload3006]

Every time the question of what's good for measuring reloading stuff comes up the helpful professional machinests lay B&S, Starrett and Mitutoyo on some poor guy just trying to do better work on his ammo. Fact is, the 'cheap-o' Chinese micrometers and calipers are astonishingly good and a bargain for anyone not making his living using the tools ever day for decades.

I do have a very precise 1" B&S micrometer reading in tenths and a Swiss made vernier caliper that's easily accurate to a thousant across it's 6" range. I also have three Chinese mics in an inexpensive set with full range test blocks of 1", 2" and 3", two Chinese 6" dial calipers, one 6" digital caliper and one 12" Chinese dial caliper in my shop. As checked on my Jo blocks, they are virtually as 'accurate' as my high cost pro-grade tools,

Thing is, if I drop any of them on a concrete floor they are shot no matter how much they cost but I can buy some 10-15 Chink replacement tools for the cost of a single B&S, Starrett, etc. The economics of that has driven a LOT of small proffesional machine shops to stock Chinese/Harbor Freight stuff for all but the most demanding work. SO - I have my good stuff carefully locked up in the shop but I'm quite happy to use Harbor Freight stuff in my reloading room - and for most of my machine work too.

You are pretty much right on but I would add if you drop your Starrett on the concrete floor chances are you F-ed it too. My biggest complaint about a lot of people I argue for the best you can afford but just because it says Starrett or Brown & Sharpe or Mitutoyo doesnt meant that you will be able to use it accurately. There were a lot of machinists I worked with for years I was one of them who thought that I could "Feel" measure within .0001 I learned I could not. Honestly no human can. that is why they came up with non feel Micrometers. But the average reloader does not need anything near this accuracy I swage and I do not. but the tenthousandth vernier scale on my Micrometer gets me as close as I need to be. its as close as most machined parts need to be. Until you get into bearing surfaces and classes of fits a regular micrometer is all you need and for the home loader a Chinese made el-cheapo will probably do all you need.

[theperfessor]

Many revolver lovers own pin gauges. Those are a pretty good tools for checking across the range of a 0-1 mic. Of course if you don't have a set that's another story.

I love good tools, but most folks doing typical reloading tasks just need good-enough tools. I have had Asian-import tools that were good and some that were out and out junk. I have also had brand name tools that were junk also, but maybe not as many.

For our lab I can't buy Starrett, simply because like most school shops tools get broken before they wear out, and I've got a limited budget to draw from.

If there is any kind of trade school or other public institution near by get to be friends with the teachers. If you lived in Southern Indiana I'd be glad to let you come in our lab and use our standards to check your tools; I bet most other schools would also.

[ricksplace]

http://www.cdcotools.com/index.php

This guy carries pretty much all chinese stuff, but the quality is usable and the prices can't be beat anywhere. Fast shipping too.

I bought a new 5" 3 jaw chuck for one of my lathes. It cost me a little over $100 for the chuck and the backing plate. The specs on the chuck guaranteed .003" total indicated runout. After careful fitting to the backing plate, a test bar runs .0005" TIR one inch from the chuck. I have a 5" Bison on my other lathe (at 5 times the price). The TIR on the Bison is .001. Go figure...