Technical Information for Gunsmiths and for Classic Car Enthusiasts

Tooling for Gunsmiths

Magazine Catch Jig

For Colt 1911 Pistols

Related tooling (available from Brownell's, Inc.):

  • Silvaloy 355 Silver Solder .005" Ribbon
  • 20 LPI Checkering File (SN 360-310-401)
  • 30 LPI Checkering File (SN 360-310-411)


The magazine catch jig is designed to allow the magazine catch to be chucked in a lathe to perform machining operations on it. It is composed of an aluminum body with two set screws. The set screw on the side is used to secure the magazine catch in the jig. The set screw in the rear can be used to set the depth the magazine catch can enter into the jig.

There are two primary uses of this jig. The first is to allow machining of the catch after it has been extended by silver soldering on an extension. I use this extension on both competition and self defense pistols. These instructions cover this application.

The second use of this jig is to secure the magazine catch in the lathe chuck when installing an oversized magazine extension which requires the catch to be drilled and tapped for the oversized extension. If you are making this type of installation, refer to the instructions provided with the oversized magazine catch button. This type of magazine catch should be installed only on pistols used exclusively for competition, never on a self defense or duty pistol due to the danger of inadvertent magazine release.

Using the jig:

  1. Remove the magazine catch from the pistol then remove the locking plunger and spring. Clean well to remove the accumulated crud.
  2. Many of the magazine catches seem to be surface hardened and may be more than file hard. Use a belt sander to remove metal down below the original serrations. If you do not have a belt sander, use a bench grinder and then file the end square. This may be done with the catch installed in the jig.
  3. Install the catch in the jig (if not installed at step 2).  The catch should be installed so that the major diameter is just inside the jig with about .150" projecting from the front of the jig. Secure the catch in place with the set screw.
  4. Put the jig into the lathe chuck. While a three jaw chuck can be used, I prefer to use a four jaw chuck and to dial in on the projecting end of the magazine catch. This allows a more accurate set up. After the catch is dialed in, loosen the set screw and remove the catch.
  5. Cut a piece of steel to be soldered onto the magazine catch. I normally use a piece of 1/8" cold rolled steel for this. It should be slightly larger than the .285" diameter of the magazine catch button.
  6. Install the magazine catch in your bench vise and silver solder the extension to it. After cooling, rinse the piece in hot water to remove the extra flux.
  7. Re-install the magazine catch into the jig. Make a facing cut to square up the new front of the button. Then make a cut to trim the extension down to the same size as the original button.  Remove the jig from the lathe.
  8. Install the magazine catch and jig into your bench vice.  At this point you can either use a 20 line per inch (LPI) checkering file to cut serrations (as per the original) or to checker it. A 30 LPI file can also be used, but 20 LPI duplicates the original serrations.
  9. Use a Craytex wheel to remove the sharp edge on the periphery of the area just checkered/seated. Reblue to match pistol.
  10. The extended magazine catch can now be pushed far enough into the pistol to allow it to bind the magazine after release.  Installing the catch into the stripped frame will allow this to be seen. Cut a pin of about 1/16" diameter to a length of about 1/8" and install it into the magazine catch spring. Then attempt to install the magazine catch plunger. If it does not go in enough to allow the plunger to engage the disassembly slot, trim the limit pin slightly until the catch plunger will just enter the disassembly slot. Re-install the magazine catch and test to ensure that it cannot bind the magazine. The limit pin provides a positive stop allowing the magazine catch to be pressed without any possibility of magazine bind.


This jig is designed to be use by the trained, qualified professional. Neither L. Bengtson Arms Company, nor retailers of its products assume any liability for incorrect use of these products. The decision as to whether the purchaser/user of the jig can competently and safely use this product rests solely with the purchaser/user.   REMEMBER--ALWAYS CHECK ALL OF THE SAFETY FUNCTIONS OF ANY FIREARM YOU WORK ON PRIOR TO RETURNING IT TO THE CLIENT.

Copyright © 1999 by L. Bengtson Arms Co.