which neck wall thickness measuring tool?

[nra-for-life]

hi everyone...

im in the market for a tube micrometer or other such tool to measure the thickness of my case necks... what are you using and how do you like it????

I was thinking of a mitutoyo tube mic for hi but would it be better to pay for the km modded one or possible the tool from sinclair that has the stand built into it? give me your opinion please. Thank you.

 

[Zia Hunter]

I use the Sinclair/Starrett neck thickness mic. Very accurate.

 

[TAB]

I have the K&M modified Mitutoyo. The chamfer is really nice when checking short necked brass like the .223 Rem.

TAB

 

[Phil]

I too use the one Sinclair offers...

No complaints here.

 

[Codeman]

I was using a standard tube mic, but have found the redding unit with the interchangeable pilots and dial indicator easier and faster to use. And easier on the eyes

 

[Bulseyetom]

I have a Mitutoyo ball micrometer from Sinclair, list price $164.95 that is virtually new in the case that I will sell for $115.00 shipped to your door. I am trying to fund custom dies for a wildcat. Tom

 

[mikecr]

Another Sinclair user

 

[Steve Blair]

Another Sinclair user

[br]
ditto

 

[bozo699]

Another Sinclair user

I like this one the best of all that I have, some don't come with the stop you can see on the front of mikecr's Micrometer, witout it,it is hard to be consistent in your measurments so if you buy one without it isn't hard to attach one and it will be well worth it.
Wayne.

 

[jlow]

Depends on your needs and budget. I use the Mitutoyo Digimatic with 0.00005” accuracy and ratchet stop. It is super quality and I like it a lot but it is not for everyone.

http://www.amazon.com/gp/product/B001VXNYW6/ref=oh_o01_s00_i00_details

I pair it with this deluxe micrometer stand which also works well.

http://www.amazon.com/gp/product/B001CTJNTM/ref=oh_o06_s00_i00_details

 

[nra-for-life]

wow jlow, nice setup there!

hey wayne i was looking at the sinclair tool on their website it does not show the "stop" or "holder" that is present on mikecr's in the picture... how/where do you get the one with the stop???

 

[bozo699]

wow jlow, nice setup there!

hey wayne i was looking at the sinclair tool on their website it does not show the "stop" or "holder" that is present on mikecr's in the picture... how/where do you get the one with the stop???

I don't know, mine came without it so I had my smith put one on it for me, looks almost identical to Mikes.
Wayne.

 

[Steve Blair]

Depends on your needs and budget. I use the Mitutoyo Digimatic with 0.00005” accuracy and ratchet stop. It is super quality and I like it a lot but it is not for everyone.

http://www.amazon.com/gp/product/B001VXNYW6/ref=oh_o01_s00_i00_details

I have several Mitutoyo micrometers advertising the same accuracy. What is a little misleading is the last digit (5th decimal place) is "5" or "0" and indicates a trend, at best. A rule of thumb in QA is that the measuring instrument must have at least an order of magnitude better resolution than the parameter measured. These are certainly Ok for reloading use, measuring neck wall thickness variation of .0001. If mikes like this were used in a formal setting, they would only be used for dimensions toleranced to .001" or coarser and even that in a controlled environment. I am not taking anything away from Mitutoyo micrometers in their price range, they are a good value. If you want to perform validating inspections to .0001", a more precise instrument is required. These days, a programmed CMM is usually used to avoid handling and affecting the part under inspection. Also, have your instrument calibrated at least every two years. All moving parts and electronics are subject to wear and deterioration.

 

[mikecr]

My Sinclair measures to 0.00005" which seems sufficient for our need here.
http://www.sinclairintl.com/.aspx/pid=38161/Product/Sinclair-Digital-Case-Neck-Micrometer

Given that unturned cartridge brass tapers in thickness from webs to case mouths, you must set a datum with a stop. Otherwise, varying depth can result in false variance. Mid point works well when culling new batches by thickness variance.
I made this stop. When I used the mic Lawrence posted(which was very nice), I dropped bushings over the mandrel to set height in necks.
And you can see I moved the mic from it's base over to Sinclair's runout gauge base to save bench space.

 

[Shynloco]

I have a Mitutoyo ball micrometer from Sinclair, list price $164.95 that is virtually new in the case that I will sell for $115.00 shipped to your door. I am trying to fund custom dies for a wildcat. Tom

Picked one up on ebay last year for $75.00, almost brand new. Either seller didn't know what he had and was ignorant about it's value. Came complete with the case and original paperwork. Gotta admit it was one of my better finds up on ebay. Love using it to check each casing beck wall.

 

[nra-for-life]

Mikecr, I can see where the stop you have made would greatly increase the repeatability and accuracy of your measurements. thanks for the pictures. Im going to have copy your pattented design after i make my purchase!!! thank you!

 

[jlow]

Depends on your needs and budget. I use the Mitutoyo Digimatic with 0.00005” accuracy and ratchet stop. It is super quality and I like it a lot but it is not for everyone.

http://www.amazon.com/gp/product/B001VXNYW6/ref=oh_o01_s00_i00_details

I have several Mitutoyo micrometers advertising the same accuracy. What is a little misleading is the last digit (5th decimal place) is "5" or "0" and indicates a trend, at best. A rule of thumb in QA is that the measuring instrument must have at least an order of magnitude better resolution than the parameter measured. These are certainly Ok for reloading use, measuring neck wall thickness variation of .0001. If mikes like this were used in a formal setting, they would only be used for dimensions toleranced to .001" or coarser and even that in a controlled environment. I am not taking anything away from Mitutoyo micrometers in their price range, they are a good value. If you want to perform validating inspections to .0001", a more precise instrument is required. These days, a programmed CMM is usually used to avoid handling and affecting the part under inspection. Also, have your instrument calibrated at least every two years. All moving parts and electronics are subject to wear and deterioration.

The gauge seems like overkill but in reality it is just about right. What sleepygator says is basically correct which is the Mitutoyo basically allow you to measure to the 0.0001”, which for our purpose is just about what you need since the neck thickness is usually around 0.01”-0.02” (corrected) and so to see the variance, you need to be able to measure reasonably accurately down to the 0.0001”.

I don’t think it makes sense to measure any more accurately i.e. 0.00001” since when you turn the neck, the mandrel the case is sitting in has about 0.001” slop and so that variance is not going to let you turn too much more accurately than 0.0001”.

 

[spclark]

I like the Sinclair tool. Certainly accurate enough for my needs, easy to read.

 

[tenring]

I started with a Starret tubing mic which went only to three deimals. Then bought a Mitutoyo and had Ken Markle hone the anvil to a .0010" taper. I luv it. Its the only way to measure short necks, i.e., .223.

 

[hogan]

Have both Starrett and Mitutoyo Replaceable Pin anvil micrometers. They read to .0001". Change pin diameter as necessary to allow smooth rotation. Would be awesome if used with a pin gage set, one item I don't have. Mitutoyo is more user friendly, Starrett is more compact.

Also have a Starrett tubing mic and the anvil head is too large for small bore ctgs.