Indicator point size for barrel work

[Rich S]

Getting ready to buy a long stem indicator. I am interested if there is a preference in tip diameter when indicating in a barrel. I currently use 0.080" diameter and it seems fine.

 

[Dusty Stevens]

Where you gonna get one? I heard they quit making the real deal now you gotta just put a long stem on a regular indicator and lose all sensitivity

 

[Dusty Stevens]

And the ball needs to be smaller than the smallest bore youll indicate. I use the smallest ruby (cant remember the size)

 

[charlieyankeesierra]

MSC still has them.

 

[Rich S]

If your referring to the Interapid 312B-15 or 312B-3, they seem to be available in a number of locations.
I was initially gong to installed the 2.75 point on a Mitutoyo 513-512. It will loose some resolution but figured I'd give it a try since I already own the indicator.
For comparison, 1/2 revolution of the long stem interapid is 0.015", the Mitutoyo with the long stem will be ~0.019". The Mitutoyo also has a profile that will extend in a chamber.

 

[47chevyCOE]

Just a heads up....msc has the interapid long reach on sale right now. I ordered one yesterday.