M1911 in 9mm or Other Calibers

M1911 in 9mm or Other Calibers

Defense Distributed’s 80% M1911 frames are manufactured by Stealth Arms, available here.  The 9mm multi-caliber frames are differentiated by the Clark/ Para-Ramp barrel seat shown above.  If milling non-45ACP keep the following things in mind: 

1.  Selecting the Appropriate File  

The M1911 mill+barrelseat+drill.dd file is designed to complete a standard barrel seat for a .45 ACP in both government and commander size frames.

The M1911 rails+drill.dd file is designed to complete 80% frames with a pre-milled barrel seat and will complete both government and commander size frames in 9mm, .40 cal, and 10mm.

When completing 80% 9mm M1911 frames with a pre-milled barrel seat, run M1911_rails.dd then M1911_drill.dd found in Cutting Code/M1911 Code/Additional M1911 Code.

Run the barrel seat operation followed by the drill operation. It's best to run rails+barrel seat in at the same time to avoid redoing the initial tolerance checks. Ideally, once you have the jig-frame oriented correctly for the rails operation, it should stay in the same position for the barrel seat operation.

2. Tolerance Checks 

Tolerance checks are built into the 1911 program to check that the frame is no more than 0.008 inches out of square. This is done to avoid cutting a misaligned rail. Passing the z tolerance check requires allowing the machine to orient the jig-frame assembly on the t-slot table so that it is parallel to the x-y plane.

Start with the jig-frame assembly parallel to the t-slot rails, gently snug the right side bolt and leave left side bolts slightly less tight so that the left side of the jig is able to slide back and forth along the z axis, but not so loose that it allows for play in the part in any other direction. Once it initially probes the part, it will compare the distance plunged on the right side to the left side and if it is more than 0.008 inches it will return a tolerance check failure.

The tool will then attempt to push the left side of the jig-frame within tolerance based on previous probes. If the left side is too far forward, you are prompted to push the left side of the jig into the tool. Once aligned, snug bolts and continue probing, repeat checks until passed.