Custom 1911 Project: Part 6- flat top and chain link top of slide

Custom 1911 Project: Part 6- flat top and chain link top of slide, presented by and Brownells

This is the sixth installment of our Custom 1911 project- in this post we are going flat top and chain link the slide.

  1. Custom 1911 Project: Part 1- getting started
  2. Custom 1911 Project: Part 2-undercut trigger guard
  3. Custom 1911 Project: Part 3- fit and blend grip safety
  4. Custom 1911 Project: Part 4- Machining a chain link front strap
  5. Custom 1911 Project: Part 5- milling the slide for low mount sights
  6. Custom 1911 Project: Part 6- flat top and chain link top of slide
  7. Custom 1911 Project: Part 7- machining ball cuts on a 1911 slide

custom 1911 full right side of pistol

Our custom Remington R1 is outfitted with the following Wilson Combat parts:

Machining a flat rib and chain link pattern across the top of the round 1911 slide adds a distinctive custom touch.

Before we proceed, please read the following disclaimer:

Warning:  The contents of are produced for informational purposes only and should be performed by competent gunsmiths only. and its authors, do not assume any responsibility, directly or indirectly for the safety of the readers attempting to follow any instructions or perform any of the tasks shown, or the use or misuse of any information contained herein, on this website.

Any modifications made to a firearm should be made by a licensed gunsmith. Failure to do so may void warranties and result in an unsafe firearm and may cause injury or death.

Modifications to a firearm may result in personal injury or death, cause the firearm to not function properly, or malfunction, and cause the firearm to become unsafe.

flat top 1911 slide indicator

You might think you could simply place your 1911 slide in the mill on a set of parallels and machine the top- you’d be in for a surprise.  All 1911 slides are tapered, they are taller in the rear than the front with the bottom not parallel to the top.  This means you need to get creative with the set up.  I placed a set of 1-2-3 blocks (2-4-6 blocks would have worked better but I don’t have a pair) on a set of parallels inside the milling machine vise.   Small clamps were threaded into the 1-2-3 blocks and the slide was clamped (with card stock to prevent marring).  A dial indicator was used to ensure the top of the slide was parallel to the mill’s x-axis.


A side view of the set up.  The 1-2-3 blocks need to sit firmly on the parallels so the slide does roll forward.  The clamping blocks need to remain on the blocks, if they are placed on the vise the entire setup will cam out of the vise as they are tightened- don’t ask me how I know.

flat top 1911 slide set up 2

A third view of the set up.

flat top 1911 slide running end mill

I decided to stop the flat top treatment short of the front sight, similar to what Wilson Combat does on their custom guns.  To machine this cut I take light passes with a 3/8″ solid carbide four flute end mill.

flat top 1911 slide second pass

I like to take a few passes for a nice smooth cut.  It is a shallow cut, no sense in rushing things and getting inferior results.

flat top 1911 slide depth for chain link

The top of the slide will have the same chain link pattern as the front strap, main spring housing and trigger guard- a custom touch that will tie the gun together.  The 1/16″ radius cutter is placed in the mill.  I use the electronic depth gauge to ensure the cutter will machine down the center of the slide.  The human eye can pic up discrepancies as small as a few thousandths of an inch, any mistake would look awful! The freshly machined flat top is coated in Dykem to increase visibility of the cuts.

flat top 1911 slide chainlink cut series 1

I run the cutter at a relatively low speed (550 RPM) and make a series of cuts .010″ deep at a .200″ interval.

flat top 1911 slide front textured

The top and bottom rows are .076″ above and below the center row with the same .200″ spacing.  Note how I laid out the cuts so the pattern “points” forward.

flat top 1911 slide rear of slide machined

The same process is repeated on the rear section of the slide behind the ejection port and in front of the rear sight.

flat top 1911 slide finsihed slide work

With the slide removed from the mill the Dykem is cleaned off and sights installed.  Looks pretty good doesn’t it?

custom 1911 top of slide

Here is the pattern on the finished gun, I’m happy!

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