What is the best way to measure the inside neck dia.

[kbstenberg]

When I resize my rifle brass I use a Lee Collet sizing die adjusted to just hold the cast bullet. But I still wonder if my cases are too tight on the bullets.
I can measure the inside dia. of the necks with my calipers (using the 2 small ears to measure inside measurements) But I am not to confident I am getting the correct measurement. Using this system.
Yes I know I can pull a seated bullet and see if the bullet was resized. I suppose in the long run. If the bullet was not resized I should just stop worrying
But is there a better way to measure any inside dia.? Kevin
Thank you in advance for any thoughts.

[jmorris]

They won't tell you if it is round but a pin gauge set would cost less that a bore mic.

[theperfessor]

For measuring inside diameters between 0.125" and 0.500" I use a set of split-leaf type small hole gauges and an outside micrometer. i use the half ball type, here is a page from MSC, the gauges are at the top of the page.

https://www.mscdirect.com/browse/tn/?searchAheadTerm=small+hole&searchAhead=true&hdrsrh=true&typahddsp=Small-Hole+Gages&navid=12107846

My personal opinion, Starrett and Mitutoyo are good but a little pricey, I have been very pleased with all the SPI tools I've bought recently.

[sprinkintime]

I think if you can afford it buy a second hand set of bore gauges to cover that dia., you will be able to check out of roundness and size, a good set will run about 300 used. Sprink

[littlejack]

+ 1 on what theperfessor said.

I purchased a set off of flea-bay for a song. They work just fine.