1911 Original Government Specs


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The Dutchman
September 20, 2009, 05:40 AM
Hey guys, Old Fuff and 1911Tuner if you're out there and you could answer I would appreciate it dearly. Does anyone know on the original JMB specs which parts were specified to be forged steel and what kind of steel alloy and heat treating specs were specified in the original design? Thank you all very much for your time.

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Old Fuff
September 20, 2009, 09:31 AM
I have a problem: I sort of have what you want, but it's not where I am. I will bookmark this thread though.

Over the years, material and heat treating specifications changed, so for example some of the parts that were made during the earlier years were not still being made the same way by World War Two, after which Uncle Sam bought no more. They did buy parts, excluding frames, to rebuild the pistols they had.

You can purchase a full set of USGI blueprints, and the material and heat-treating specifications are on each individual part's drawing. But these represent the pistol as made during World War Two and rebuilds thereafter.

Besides the frame, slide and barrel most of the lockwork was made from forgings. At one time this included the grip safety, safety lock, mainspring housing, slide stop, magazine latch, extractor, hammer, sear, disconector, barrel bushing, and trigger. I'm not sure about the firing pin stop, but I believe so. There could be more, but I'm going by memory.

Obviously times have changed, but the manufacturing economy and technology was entirely different. Also cost cutting and bean counters were not the principal consideration that determined what would be built and how.

1911Tuner
September 20, 2009, 11:59 AM
Dutchman, the original specs didn't call for any heat-treating, and the guns were dead soft ordnance steel...whatever was in use at the time.

In 1936, Colt added a hardened steel insert in the breechface to address the problem of recoil peening in that area, and it worked very well. If you look closely at a clean breechface on a WW2-era GI pistol, you can see the circular insert that many mistake for a machining mark. Along the same time, the slides were spot hardened in key areas, which made the finish slightly darker in those areas. The end of the slide, about two inches back from the muzzle...at the thumb safety notch...and at the slidestop engagement notch. Aside from that, they were soft.

Then, in 1946...full hardening of the slides was incorporated for all end-run military contract replacements and commercial Government Models. Frame hardening followed shortly after, but I'm not sure exactly when. Fuff will provide the details on that. He's got sources that nobody else seems to have.

The Dutchman
September 20, 2009, 02:31 PM
Hey guys thank you very much for your responses. Should I assume that the ordnance steel was 4140 or 4142? I sure wish the modern manufacturers still used the original plans that JMB intended from the start.

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