Customizing the 1911: machining a golf ball front strap

Hot and sweaty or cold and numb hands can make grasping your 1911 pistol difficult, especially if it has the original specification smooth front strap.  The addition of checkering, texturing, rubber grips or grip tape can all help.  While checkering looks great, it has sharp edges that can wear thorough clothing and become damaged with rough handling.  Textured finishes like chain link and golf ball patterns offer increased texture with more more durability and fewer sharp edges.

The golf ball pattern first showed up on 1911’s in the form of G10 grips.  From there, a few different custom gunsmiths adopted it for the metal parts of the gun, including the front strap and mainspring housing.

In this post, I’ll machine a “golf ball” pattern into a 1911 front strap.  Trying to figure out how to cut this pattern was difficult, the depth of cut, cutter diameter and spacing all weigh heavily into the final look of the pattern.  Since it is a custom gun feature, you just have to like the way it looks when you are done.

Before we proceed, please read the following disclaimer:

Warning:  The contents of Rifleshooter.com are produced for informational purposes only and should be performed by competent gunsmiths only. Rifleshooter.com 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.

The frame shown is from a stainless steel Colt Series 80 Officer’s ACP.  This gun has been around for years. I originally bought it used in 1994 and have had it largely relegated to the back of the safe since.  At the time I purchased it (as well as a Lightweight Officer’s ACP) I was unaware of the cycling problems associated with these compact 1911s.

Prior to any machine work on the frame it pays to take time to plan accordingly.  A mistake can permanently alter the frame and turn it into an expensive paperweight.  I like to measure the thinnest point of the front strap to ensure that enough material will be left after the cuts are made.  For reference purposes, a schematic of a Colt Officer’s ACP can be found here.

I ordered the following projects from Brownells for use on this project:

golf-ball-1911-front-strap-layout

The “enhanced” Colt’s have a frame that has a high cut underneath the trigger guard.  This saves a step on the machining process.  I coat the flat area of the frame with some Dykem layout fluid to make the pattern more visible as I machine it.  I placed some painters tape on it to prevent the Dykem from running all over the frame.

golf-ball-1911-front-strap-on-fixture

Next, the frame is placed on the fixture I had made to secure it in a rotary table chuck.  For more information on making this fixture, see Custom 1911 Project: Part 4- Machining a chain link front strap.  The fixture consists of an arbor and clamping block that are inserted through the frame.

setting-up-fixture-golf-ball-1911-front-strap

Next stop, the milling machine.  This is a standard Bridgeport knee mill.  I am using a 10″ rotary table with 3 jaw chuck and a tailstock.  The frame is secured inbetween the chuck and the tailstock and the fixture is aligned along the x-axis.

golf-ball-1911-front-strap-dialing-in

The rotary table is set to “0” and the chuck is loosened.  The frame is aligned perpendicular to the table with a small level and frame is checked with a dial indicator to make sure it is still aligned.  Setup for an operation like this is absolutely critical, check everything twice, then check it again.

locating-center-golf-ball-1911-front-strap

To locate the center line of the frame I use an edge finder and set the mill’s digital readout (DRO) to 0.0000″.

14-carbide-end-mill-golf-ball-1911-front-strap

The cuts for this pattern are made with a 1/4″ ball nose end mill.  Each cut is spaced .150″ apart and .025″ deep.  The quill is locked on the mill and the plunge cut is made by raising the z-axis.

cutting-golf-ball-1911-front-strap

After a pass is made, the table is rotated 10 degrees.  The process is repeated, but this time with the cuts staggered by .075″, thus creating the diamond pattern.

golf-ball-1911-front-strap-cutting-2

I’d imagine this is an easy process on a CNC mill, for a manual machine you need to stay sharp and pay attention.

golf-ball-1911-front-strap-finally-finsihed-on-mill

Finally, the frame is ready to come off the mill.  So far, so good!

golf-ball-1911-front-strap-file-2

I broke the rough edges with some 220 grit abrasive paper and then blasted the surfaces with some aluminum oxide (I’ll be Cerakoting it when the pistol is completed).

I used a 4 flute end mill to cut this pattern, unfortunately it left some tooling marks that need to be removed with a Cratex abrasive point.   In retrospect, a 2 flute cutter would work better, since it doesn’t have the extra two flutes to scribe a mark in the cuts.

custom-officers-grey-with-light

The finished pistol was coated in Cerakote, McMillan Grey.  The outstanding Fenix tactical flashlight compliments it well!

custom-officers-grey-front-strap

The finished grip looks and feels great!  Golf ball texturing is a welcome addition on any 1911 I own!

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