Redneck Concentricity Gauge

[.30/30 Guy]

I took my C-H case trimmer and added a support for the dial indicator. Now I have a redneck concentricity gage. Put a loaded shell in the case holder, zero the dial indicator and rotate the shell holder. Seem to work OK.

[CuZ]

Needs some bailin wire and duct tape; other than that... well done!

[TNsailorman]

Good thinking 30/30 Guy. That may be one of my winter projects. Thanks for the idea. James

[Doc Highwall]

Actually I think that is the best way to check runout because it is closer to how the case will be held when it is in the chamber upon firing.

Indicate both the inside and outside of the case holder, if there is no runout you are good to go with both cases and loaded ammo.

[gcsteve]

I didn no rednecs coud spel consentrisity. See wat I meen?

[gray wolf]

Indicate both the inside and outside of the case holder, if there is no runout you are good to go with both cases and loaded ammo.

I doubt you will see zero when you do the above. I would be very surprised if the case holder and the bed of the trimmer is plumb. I haven't seen a case holder that held the case concentric to the walls of the case.
However, it's great idea.

[Green Frog]

Was the wooden bracket reused from an old beer case? If not, are you sure you're not a faux redneck?

Froggie

[.30/30 Guy]

I took the shell holder and put magic marker marks at 12, 3, 6, an 9 oclock. I then repeated a test using the same loaded round orientating it at each mark. Results varied by a couple of thousands. Good enough for me.