1911 slide/frame mismatch


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Ohlar
January 22, 2005, 03:55 PM
While I'm rather use to juggling several variables, at somewhat close tolerances, in my guitar building/repair work, I am new to 1911 tinkering. I've recently pickup both vols of Kuhnhausen's books. What a world of information, however I am in need of some clarification on a few points.

The case at hand is a Government model parts gun made up from an Essex frame, a slide marked TZ on right and a 7 digit ser# on left, a barrel marked "P" on one side and an "O" in a square on the other side. The remaining parts are of nondescriped origin. Clearly a project gun. Despite the lack of pedigree, the pistol functions and shoots POA as is. The most glaring shortcoming is that the slide sits almost 1/16" forward of the frame when in battery. Kuhnhausen suggests recontouring the back of slide/frame (vol II, page 133). Altering these parts seems drastic at this point. There is more for me to learn first. My guess is that the barrel was poorly fitted to begin with. I have a Springfield take off barrel of the correct length. Perhaps it may be fitted in place of the existing barrel. The slide stop hole on the left side of the frame is a bit warbled out of round. The bottom of the slide shows signs of rubbing, finnish wear, in the frames dust cover.

Any comments? How the about origins of slide and barrel? I have jumped around a bit in the books without reading in their entirety so far. Maybe your best comment will be, READ THE BOOKS! Thanks, Ohlar

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Old Fuff
January 22, 2005, 04:52 PM
Yup, you do have a "project" there: :neener:

Look at the barrel more carefully and see if the letter inside the box is a "C" rather then "O." I think the "P" is a proof mark, and if the barrel is marked with a C-in-the-box you have a World War Two or Post-war USGI barrel made by Colt.

I'm not sure about the slide, but it may be a post-war USGI slide made by a contractor around Korean War time. I think the number in question is a stock number.

The misalignment you mention is likely caused by the Essex frame. They are often out-of-tolerance, especially earlier ones. If possible, assemble the slide and barrel on another (non-Essex) frame and see how they line up. This won’t solve any problems, but it will give you a clue.

There isn't much you can do with the frame you have, except re-contour it to match up with the slide. The other (expensive) solution is to buy a different frame. Normally I wouldn’t suggest this, but if all of the other parts (slide, barrel, lockwork etc.) are USGI or older Colt commercial it might be worth getting a better frame. However don’t do this until you know exactly what you do have.

1911Tuner
January 22, 2005, 05:36 PM
Good information from Fuff. Sometimes the tolerances stack up the wrong way...especially with some of the older Essex components.

The elongated slidestop pin hole is a player in the slide sitting too far forward,
as it will allow the barrel to move farther forward before stopping. Where stoppeth the barrel...there stoppeth the slide very closely. The egg-shaped hole is likely either due to normal wear in a high round count gun...or evidence of somebody letting the slide slam on an empty chamber repeatedly.
Since cast frames of questionable quality generally crack before they wear out...I'd guess that this is what happened.

If you have a dial caliper, measure the thickness of the tips of the barrel lug feet, back to front. If the barrel has been correctly fitted, or is within spec,
the feet should be about .115-.120 inch thick. If they're thinner than that...or show evidence of being peened rearward during the empty slide slam trick...that will also contribute to the misalignment. If they're badly peened...or cut below .100 inch thick...the unlock timing could also be
delayed, and may cause some problems as well.

Luck!

Tuner

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