PDA

View Full Version : 1911 half cock notch


Gregory Gauvin
April 12, 2009, 12:29 PM
My half cock notch functions correctly. However, when I try to pull the trigger when on half-cock, the hammer does not drop (as it shouldn't) but I notice that the hammer ever so slightly moves backwards. Very minimal movement, but I wasn't sure if the hammer should move at all. Something is making contact. Is this a problem, what is causing this?

goodspeed(TPF)
April 12, 2009, 12:55 PM
:eek: Stop it. You're going to ruin your sear.

HammerBite
April 12, 2009, 02:07 PM
Stop it. You're going to ruin your sear.
Yeah, what he said!

There is an overhanging lip on the safety notch, the purpose of which is to trap the sear so that it won't lift when the trigger is pulled. There is a bit more space under the lip than is required to accommodate the sear, so the sear is free to move a little bit. The rear face of your safety notch is apparently cut at a slight positive angle, which causes the sear to overcock the hammer as the sear tries to lift out of the notch.

You do not have a problem.

You may develop a problem if you yank the trigger hard enough with the sear in the safety notch. You may snap the nose of the sear off.

Harry Bonar
April 12, 2009, 03:35 PM
Sir;
I suppose you could call it a "safety" notch but it is really to catch your hammer if it "follows" to keep your weapon from going full auto!
Many of the new hammers do not even have a notch but a flat ledge for that purpose!
Harry B.

JMBstudent
April 12, 2009, 07:49 PM
I really don't understand why some of the aftermarket hammer makers have abandoned the trapped half cock notch.
The trapping function significantly improves the safety of the pistol.
Am I missing something?

HammerBite
April 12, 2009, 08:12 PM
I really don't understand why some of the aftermarket hammer makers have abandoned the trapped half cock notch.
I strongly suspect that it is a cost saving measure.

James K
April 12, 2009, 10:22 PM
No, it was because some folks kept resting the outside of the half-cock notch on the sear, called a "false half-cock." In that condition, if the trigger is pulled, the hammer will fall just far enough to fire the gun.

The ledge is positioned lower; it will still serve to catch the hammer if it falls off full cock, but is too low to allow the hammer enough momentum to fire the round if the trigger is then pulled.

Actually, the evidence is that Browning intended the half-cock not only to be a safety, but to be the only safety on his hammer guns. That not only included the auto pistols prior to the special 1910*, but also his rifles and shotguns. Only when the hammer was concealed, did Browning use a manual safety.

This should not be too surprising. A half-cock or a safety notch was the normal means of making a revolver safe in those days, so it was not considered either strange or inadequate for use on an auto pistol.

The exception was the Model 1900 sight safety, which was a Colt idea. The manual and grip safeties of the M1911 were installed at the insistence of the army.

*The pistols did have an inertia firing pin, but that was not true of the rifles and shotguns.

Jim

Scorch
April 12, 2009, 11:44 PM
I really don't understand why some of the aftermarket hammer makers have abandoned the trapped half cock notch. Because the Series 80 pistols hammers are built that way, the "half-cock" is actually a shelf just above where the hammer would fall to at rest, so the capture is not necessary. But in Series 70 and earlier guns, definitely use a capture safety notch.

JMBstudent
April 13, 2009, 12:32 AM
Great info Jim Keenan and Scorch. Thank you.

Gregory Gauvin
April 13, 2009, 05:01 PM
I've also seen hammers that have the half notch safety and lower capture. (If I said that correctly). What I mean is that, I saw a commander style hammer that will cock that tiny bit like a Springfield GI, but will cock further to a half notch safety, and then cock to fully rearward position.

"No, it was because some folks kept resting the outside of the half-cock notch on the sear, called a "false half-cock." In that condition, if the trigger is pulled, the hammer will fall just far enough to fire the gun."

- Why would anybody rest on the outside of the half-cock? The only time I could conceive myself doing this is I'm function checking or playing with my [unloaded] pistol.

James K
April 13, 2009, 06:19 PM
"some folks kept resting the outside of the half-cock notch on the sear, called a false half-cock."

It was seldom done deliberately, but a lot of people used to carry the 1911 on half cock. (It is not done much any more, but at one time it was very common.)

The user loaded the chamber, then lowered the hammer by hand attempting to put it on half cock but instead left the outer "arm" of the notch resting on the tip of the sear. (It sounds weird, but it is rather easy to do; if you try it make sure the gun is not loaded.)

Jim