1911 hammer half-cock notch

[White Horseradish]

I have a couple of hammers that I got in a lot of parts. I was thinking of maybe putting one of them into my RIA. However, when I compared them to the original I noticed that the half-cock notches were really shallow. On one of them the sear rests on the notch, on the other it barely catches it.

This doesn't look like a feature to me, I don't think they could keep the hammer from falling. I am curious as to what could cause this. Inept modification? Breakage?

Also, if I really wanted to use that hammer, can the notch be fixed?

 

[Old Fuff]

Well first of all, it might depend on who made the hammers. The sear should seat all of the way into the notch, and the lip should be deep enough so that you can't release the hammer with a very hard pull on the trigger. Also, look to see if the finish is polished off, indicating that someone "reworked" or cut the notch down.

The notch should be .035" to .040" wide, (check with feeler gauges), and deep enough so that the sear (or feeler gauge) can't be pushed out of engagement.

If the notch is otherwise O.K. you can slightly thin the nose of the sear from the front to get full engagement in the notch, but this shouldn't be necessary if both the hammer and sear are "made to print."

It is very important that the sear does fully engage in the notch, as this is what catches the hammer if it follows down.

 

[White Horseradish]

They are nowhere near that deep. One looks like it was made that way, the other one does have finish taken off, plus I don't think notch cornersare supposed to be rounded off.

I tried them both in the pistol. Neither notch holds.

What posesses people to do these things, I'll never know...

 

[Steve C]

You probably have the new styles of hammer. The 80 series Colts eliminated the traditional half-cock for a "safety shelf". The safety shelf catches the hammer at a much lower point in its travel than the earlier series half-cock. A pull on the trigger will drop the hammer off the safety shelf which is still safe as the hammer isn't far enough back to whack the firing pin hard enough to set off a round. The purpose of both the half-cock and the safety shelf is to catch the hammer and prevent discharge if it accidentally slips from the thumb and dropped during cocking. The safety shelf on the 80 series accomplishes the safety function of the half-cock but prevents shooters from using the half-cock incorrectly as a safe carry position which it is not. Some clones still use the old-half cock style.