Introducing the Plunkinator

[xrrcr]

I have 6 different 9mm's, all with varied oal requirements. Bought a throating reamer to standardize them.

Problem is how to measure the depth of an angle at a particular diameter. Tried optically and that sucked. 

So came up with this and wanted to share.

 

Starting from the left, that is a .3540" gage pin. It slides inside of a turned aluminum sleeve that mimics a case in the chamber. The pin slides all the way in flush with the sleeve, so that the indicator can be zeroed. Then you insert it into the chamber and a measurement from the case step to the .3540" datum line is given. My particular chambers ranged from .125" to .062" using this method. 

[Jim Watson]

I could see a market for that, and a guideline for measuring the bullet ogive to see where they clashed.  

[ltdmstr]

Plug the barrel, stuff a piece of clay in the chamber end, then pop it in the freezer.  When it gets hard, remove it from the barrel and measure.  You can also do a chamber casting with cerosafe. 

[xrrcr]

I want to use it as a comparative measurement tool not absolute. Needed something to keep track of where I was during throat reaming.

Make them all the same and then ultimately make a stub gage to use for plunking new bullet profiles.

 

 

[zzt]

I use a Go gauge and new Manson reamers.  They provide a .055" throat.  That's long enough for any OAL I load.  Having a longer throat than needed for a particular ogive does not affect accuracy.  I have a Brazos Custom 9mm barrel.  He uses a .100" long throat.  The barrel is super accurate even though I only load to 1.161" with HAPs.