[Ivan]

Hi Harry,
I am sure you have much more experience than I do with the M1911, but I don't believe the suggestion of using 240 grit sandpaper is a good one. I find that 600 grit wet/dry is sufficient in general to remove slight machine marks and sharp edges. Any coarser grit invites actually removing measureable amounts of material rather than just polishing.

The M1911 types are quite tolerant of some messing up in some areas, but I would say that there is a pretty good chance that the frame of the gun has been altered in such a manner as to take it permanently out of spec. It may still function quite well regardless:

There is a maximum distance between the lower edge of the chamber and the breech face. This dimension puts the unsupported area of the chamber over a fairly thick section of the "average" .45 ACP case. If you push it too far forward, the unsupported section goes toward a thinner area of the case. There may still be a margin for safety, but technically it is out of specification.
If the feed ramp on the frame has been altered (and that is what I am guessing happened here), In order to maintain the proper angles of the barrel and frame ramp and still allow the 1/32 inch space between barrel and frame, the lower edge of the chamber may NEED to be put so far forward as to be out of spec. If this is the case, the only way to stay within specifications may be to have a ramped barrel or a frame insert fitted. I am not saying the gun won't continue to function reliably indefinitely if this happened, but it would still be out of specification. BTW, Kuhnhausen's second book on the M1911s describes these measurements better than the first book and the numbers are not quite obvious but can be calculated.

BTW, I have had an apparent double charge from a commercial reload blow out the unsupported part of the case. The result was not pretty, but no serious damage was done:
The case vented into the magazine well.
The gas cut through and set off two other rounds in the magazine.
The magazine (a Chip McCormick) vented gas out the holes.
One medallion (from a very nice set of Colt Medallion grip panels) went out the port side and was never seen again.
The other medallion stung the palm of my right hand
Both grip panels were blown to wood scraps
The pressure compressed the mag spring PAST its solid length
The pressure swelled the magazine so that it was too wide to be extracted.
Brass scraps were blown through the ejector tunnel into my glasses and cut my forehead slightly.
I can't quite remember if the slide locked back on that shot or not but I think it did.

The "No serious damage done" was because only the grip panels and magazine were a total loss. I ended up fitting a new Kart barrel, but only because I thought the barrel looked like it was over ramped from the factory.

Regards.
- Ivan.