Friday, November 28, 2014

Jeweling a Rifle Bolt

Jeweling (also known as "engine turning" or "damascasing") gun parts has been performed on high end sporting guns since around the turn of the century.
I'm not sure who had the 1st idea, but it is a simple process that adds some "bling" to a gun.


The process has been used for other, non-gun related items as well. The engine cowling on Charles Lindbergh's Spirit of St. Louis was engine turned.
 After WWII hot rodders adopted the practice to dress up engine and dash parts
 Some cars even came with engine turned parts from the factory, here is a dash from a 1964 Chevy Impala
 The process is quite simple. 1. you polish the part to a high shine (this is important). 2. You set up a jig or vice for a drill press. 3. you create small, overlapping circles in the polished metal

There are numerous items that can be used to create the circles. In the past machinists have used pencil erasers, wood dowels, steel brushes or dedicated abrasives. Some use these tools along with a mild or medium abrasive, like jeweler's rouge, metal polish, car wax, valve lapping compound, even toothpaste.....

Here is a steel brush designed for jeweling, they are available from Midway USA 
 Midway USA also offers these Cratex brand abrasive sticks
 I ordered the 1/4" size from Midway USA, available here

I needed a vice for the drill press, I bought this cheap one from Harbor Freight, although if I had to do it over (and I still might) I would be a better quality, American made one.

 

I will be overlapping the circles by 50%.



50% overlap is not a requirement, only a rule of thumb. You can overlap more or less, you can go in straight lines or at an angle. There really are no rules, some gunsmiths and  machinists have their own pattern that acts as their "signature" 
The machinist vice that I bought moves 1/8" with every full rotation of the handle(s). This made it easy (and fast) to evenly space my circles.

I decided to start with an easy part to jewel first. A 10-22 bolt for my daughters Girly Rifle Project.

After polishing the bolt, I put it in my vice and used just the Cratex, nothing else.
 


 I liked the results, but the jeweling didn't appear very deep. So on my next bolt (from my Remington model 58 project) I decided to use some abrasive compound. I made my own using Mother's mag polish and some powder which I had on hand


Again I liked the results, but the depth of the circles was not what I was hoping for. I think I would like to try something more aggressive like a wood dowel.
One thing you should know, is that this finish is not going to be very durable, it will wear off. Some say that the jeweling actually helps prevent wear on the bolt due to its ability to hold oil better than a plain polished surface.

My next bolt will be the one from my Arisaka Redux project, but I need to build or buy a jig

There are several available, like these ones from Wheeler Engineering 
and B-Square
 Both are available from Midway USA

 Here are some different bolts & parts that have been jeweled, to provide you with some ideas and/or inspiration