Tail of two calipers

[fstdraw]

For years I've relied on my trusty Frankford Arsenal battery powered digital calipers to measure for me while reloading thousands of rounds of ammo. Friend gave me a lightly used pair of Lyman SS calipers (no batteries required) and I started to use them to measure OACL etc. Funny thing thou, both calipers measure differently. While trimming .223 cases to 1.750, tried and true FA calipers say 1.750, new kid on the block Lyman says 1.752, yikes! When measuring something of known diameter, like a Berry's 62 gr. bullet, FA says 223.5 and the Lyman says .224.

I feel so used and so wrong for so many years, who to believe and does it make THAT much difference?

Sad in Salem.

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[po18guy]

The calipers should compare favorably with bullet makers' dimensions. Try several brands. Also, are you cleaning the jaws and zeroing frequently?

 

[elsie]

You could always get a set of calibration rods to test each one.


elsie

 

[bionic knees]

.0005 difference in bullet diameter is not a big deal. toss another caliper in the mix and see what it says.

 

[Caveman Jim]

Very interesting, both my calipers, analog and digital like yours, read the same.

 

[Local Loader]

Your numbers can easily change depending on how hard or light you are pressing on the other ones. This is likely what is happening or the arms are possibly thinner so the press in more easily or possibly thicker.

 

[po18guy]

As it is with tire pressure gauges: the man with a pressure gauge always knows his tire pressure. The man with two gauges is never sure.

 

[Lilhigbee]

"A man with one watch always knows what time it is. A man with two is never sure."
Apparently a similar circumstance is true with calipers.

 

[po18guy]

"A man with one watch always knows what time it is. A man with two is never sure."
Apparently a similar circumstance is true with calipers.

Brilliant!

 

[DizzyJ]

Get a set of Brown and Sharpe and be done with it.

This coming from someone who was a journeyman machinist in a past life.

One thing I learned early on is cheap tools will more often than not lead to frustration and rework at some point down the road.

 

[Local Loader]

I just use the cheaper ones that are available but not the super cheap ones. Plus I keep a fixed size guage as well to check things that don't seem right.

 

[bionic knees]

I just looked at a half dozen "reviews" of the ten best calipers, shocked is the only way to describe what I found. every one of them listed a sub $30 caliper as the best, with Mitutoyo filling 3 or 4 of the top ten. simply amazing.

 

[P7M13]

If your eyes work, get a set of verniers. They don't rely on gears or magnetics.
Reading your data, on one of the calipers , the scale is off, which is why you are off by 1/2 thousandth at .2235 and a full two thousandths at 1.750
That's a significant problem. I don't know which one - would suggest you go to a Napa Parts store where they probably have gauge blocks for calibration (maybe call first ?).
Being off by 3-4 mils in a 338 Win Mag could be the difference between closing the bolt or not. I like to know my schnitt is a little tighter than that....

 

[DizzyJ]

I just looked at a half dozen "reviews" of the ten best calipers, shocked is the only way to describe what I found. every one of them listed a sub $30 caliper as the best, with Mitutoyo filling 3 or 4 of the top ten. simply amazing.

Who did the evaluation, and what was their criteria?

Mititoyo is good too. I'd be shocked to know those were the real deal for that price.

Here's a pair of Brown & Sharpe very similar to one of the pair I use.

Brown & sharpe 6” dial caliper black face 0.001” #599-579-5 tesa technology | eBay

This is in great shape, includes pictured hard case.

www.ebay.com

 

[ORhutner]

Get a gauge pin and measure it with both calipers. They are ground to tolerances that will allow you to verify which caliper's are measuring true or if either pair is measuring true. This is why machine shops and Q&A departments have their measuring instruments certified.

 

[DizzyJ]

If your eyes work, get a set of verniers. They don't rely on gears or magnetics.
Reading your data, on one of the calipers , the scale is off, which is why you are off by 1/2 thousandth at .2235 and a full two thousandths at 1.750
That's a significant problem. I don't know which one - would suggest you go to a Napa Parts store where they probably have gauge blocks for calibration (maybe call first ?).
Being off by 3-4 mils in a 338 Win Mag could be the difference between closing the bolt or not. I like to know my schnitt is a little tighter than that....

I've got a set of pin gauges I bought several years back that work well for checking accuracy as well.

 

[DizzyJ]

I just looked at a half dozen "reviews" of the ten best calipers, shocked is the only way to describe what I found. every one of them listed a sub $30 caliper as the best, with Mitutoyo filling 3 or 4 of the top ten. simply amazing.

This is the first one that popped up when I searched best dial calipers. I suppose "best digital calipers" may bring different results.

Best Dial Caliper Reviews: Guide & Top 10 Picks in 2023

Top 10 best dial caliper reviews, buying guides, recommendation of the best overall, best for woodworking, best for machinist, budget, etc

www.fullyinstrumented.com

 

[fstdraw]

Talk about a can of worms! OK, I'm headed to a buddy's machine shop to gauge.

Thank you to all.

 

[bionic knees]

This is the first one that popped up when I searched best dial calipers. I suppose "best digital calipers" may bring different results.

Best Dial Caliper Reviews: Guide & Top 10 Picks in 2023

Top 10 best dial caliper reviews, buying guides, recommendation of the best overall, best for woodworking, best for machinist, budget, etc

www.fullyinstrumented.com

yes, I searched digital calipers, I have Mitutoyo, and Starrett myself. for engine building and setting up differentials.

 

[arakboss]

Calipers are for elites.