Case head mic?

[shooter74]

I’m in the market for a mic for measuring case head expansion during load development. Which style anvil and shaft is best to get a consistent measurement while doing this. I’ve seen plungers, blades, etc recommended for this. Want to buy the correct tool the first go. Thanks

 

[Papa Charlie]

I would use one like this if it were me.

 

[shooter74]

I would use one like this if it were me.

I seen some like this and it looked very practical for measuring a round case in a precise location. Thanks

 

[Papa Charlie]

For what you are talking about doing, if it were me, I wouldn't worry too much about buying a brand name. I have purchased many mics off Ebay, made in China and they perform and read just as accurate as my Starrett's and Mitutoyo's, but at a fraction of the cost.
I would consider the more expense brands if I was to be using them every day in a machine shop, but for periodical use, the cheaper brands work.

 

[BoydAllen]

IMO the proper tool is a 0-1" blade micrometer. This was the least expensive that I could find. It needs to read to .0001. It should allow you to measure in the bottom of the extractor groove of a rimless case. For belted cases I have measured the belt, after putting a mark across the case head so that I would measure it in the same place each time.
https://www.ebay.com/itm/PRECISION-...486431?hash=item4cea9a2a5f:g:P2kAAOSwuPlbbZeV

 

[shooter74]

For what you are talking about doing, if it were me, I wouldn't worry too much about buying a brand name. I have purchased many mics off Ebay, made in China and they perform and read just as accurate as my Starrett's and Mitutoyo's, but at a fraction of the cost.
I would consider the more expense brands if I was to be using them every day in a machine shop, but for periodical use, the cheaper brands work.

Okay thank you I had been looking at used Mitutoyo and the likes. Finding some very reasonable.

 

[Bart B.]

For belted cases I have measured the belt, after putting a mark across the case head so that I would measure it in the same place each time.

Good idea. Otherwise, out of round cases will show different readings.