Cone Depth Fixture

[gunsandgunsmithing]

Thank you!

I’m working on a couple things that have held me up.

I want to be able to use the micrometer to measure the back of an unchambered tenon to have a reference point for the headspace when chambering a new barrel without a barrel to copy. The issue with that is every available micrometer head has a 5mm-1/4” spindle, which would go into the bore on anything larger obviously. So I’m working on a legit solution for that issue. I’ve come up with a couple ideas, but again I don’t love any of them.

My other idea is to just make it with its own built in micrometer, but that obviously has its own unique problems.

You can use a depth mic set at your desired hs dimension...say 1.115 for a Panda. Just set the depth mic and zero out your tool on that. It might not be the answer you were looking for but it's simple and free, as long as you have a depth mic. I'm sure you do.

 

[Jud96]

You can use a depth mic set at your desired hs dimension...say 1.115 for a Panda. Just set the depth mic and zero out your tool on that. It might not be the answer you were looking for but it's simple and free, as long as you have a depth mic. I'm sure you do.

That’s a good idea and I like it. Anyone chambering barrels would presumably have a depth mic too

 

[Jud96]

HS, 25° and 30° cone inserts. Micrometer is a 0-2" head.

Why a 0-2” mic? I’m just curious. Thanks!

 

[B Nettesheim]

I use at least one of these every day
They repeat every time, and solid measurements!!

 

[ridgeway]

Why a 0-2” mic? I’m just curious. Thanks!

I doesn't have to be. I calibrate the micrometer to the base of the tool so I'll have an actual micrometer distance from tenon shoulder. No need to math anything out. The extra length allows me to interchange cone inserts inside the tool. That measurement is just a reference number.