Reamer Extension

[Clemson]

I like to use short-chambered barrels, and I normally finish-ream them with the barrels installed on the actions. That takes the guess work out of headspacing so that the bolt just closes on a "Go" gauge. I thought I would walk anyone interested through the process of making a reamer extension that will allow you to do that.

 

Clemson

 

I started with a 3/8 drive socket extension. This one is a cheapie with a nominal 10" length. How cheap? I pulled it out of a box of wrench parts in my local pawn shop, and the guy behind the desk gave it to me for free! I guess that says something about how much time I spend in the pawn shop..... The extension is shown with a full-length Model 98 action to show that it has plenty of length to ream the barrel through the action.

 

 

A 3/8 drive extension is just about perfect for holding most chamber reamers. Used "upside down" the square shank of the reamer fits into the socket of the extension, and the square drive end can then be turned with a large tap wrench. A few minor operations need to be performed to get this setup to work well. The end of the extension may need to be reduced in diameter a few thousandths. This particular one measured 0.705 inches, and that is just enough that it won't quite slip through the front ring. That should not be a problem for reaming, but since you need to drill the extension for a set screw, you might as well take the diameter down a bit and make the operation smoother. The photos tell the story:

 

 

The extension stops about here:

 

 

 

I used a belt sander to reduce the diameter and to remove the chrome plating on the end of the extension, making it possible to drill the end:

 

 

[Clemson]

The next phase involves adding a set screw to hold the reamer in the square socket of the extension.

 

This is the holding setup for drilling:

 

 

The hole is for a #6 set screw:

 

 

Tapping by hand with a #6x32 tap:

 

 

The screw itself had to be shortened, so I drilled and tapped another 6x32 hole in a piece of scrap to use as a holder for grinding down the screw:

 

 

 

Voila! The finished extension with a .30-06 reamer installed and held in a large tap wrench:

 

[rwims]

Thanks Clemson, You just answered a question I've been pondering for the past few days. I have two short chambered barrels to be installed.

[Doble Troble]

Thanks, Clemson. Excellent tutorial.

[Spiris]

Well done Clemson, nothing like a visual tutorial to explain things.

Thanks again,

Spiris

[ken98k]

Much appreciated.

Kenny

[Clemson]

Thanks, guys. Sometimes it's the simple stuff that we stumble over.

 

I'll try to set up to true a receiver ring in the next week or two, and I will take pics when I do it.

 

Clemson

[flaco]

A very nicely done tutorial, Clemson.

 

Thanks-

 

flaco