1911 Pistol Magazine Drilling Jig

Helps to drill properly-spaced holes (0.531" on center) in the floor plate of a 1911 magazine, for mounting a base pad (such as my own 1911 Pistol Magazine Base Pad.)

Printing Details

I printed in PLA.  The hole on the front side can be tapped with a #4-40 thread, and a set screw used to secure the jig on the magazine floor plate.

Using the Jig

You'll want to disassemble your 1911 magazine before you start, removing the follower and spring.

There are two versions of the jig: one for guiding a #43 drill bit, and one for guiding an 8mm diameter hardened steel center punch.

I didn't actually find the drill-bit guide very useful. Magazine floor plates are just too hard to be drilled easily with a handheld drill and soft plastic guide. I broke a cobalt drill bit in the attempt.

But using the center punch to make a good divot, and a carbide drill bit in a drill press at low speed, worked pretty well.

The punch I used is 8mm diameter, and came as part of a Veritas Optical Center Punch kit.  You will probably need to modify the design to match whatever punch you have (the size of the hole is set by the “PunchHoleDiameter” parameter in the Fusion 360 file.)

After drilling the #43 hole, finish it with a #4-40 tap to cut the threads.