[FullEffect1911]

Hi,

I have a somewhat hypothetical 1911 question that I was wondering about.

Lets say that you have a cocked and locked 1911 with the safety on. Now lets pretend suddenly the sear disappears instantly.

Will the hammer fall as if the trigger was pulled? Or is the thumb safety designed as such to impede the hammer from falling in the event of a catastrophic sear failure?

[adweisbe]

The hammer will fall the instant the sear disappears. The thumb safety is not designed to impede or stop the hammer but it might slow it down depending on the dimensions of that particular gun. The thumb safety has a lug that bears directly on the sear. It is not intended to contact the hammer but it can if it is in the engaged position but this is just a side effect. of the geometry.

[Walkalong]

Theoretically, it will catch in the 1/4 cock/safety notch. In general it works pretty well as long as the trigger is not pulled. It is there in case the hammer slips from under your thumb or the sear/hammer engagement fails.

[FullEffect1911]

Theoretically, it will catch in the 1/4 cock/safety notch.

Where is the 1/4 cock/safety notch located? On the thumb safety?

I know of the 1/2 cock shelf located on the hammer of course but am unfamiliar with the 1/4.

[Master Blaster]

Does the sear disappear to another location on Planet Earth, or does it transmute to another dimension outside our universe?

[FullEffect1911]

Does the sear disappear to another location on Planet Earth, or does it transmute to another dimension outside our universe?

Let's go with sucked into a black hole and off to another dimension. But sucked up in such a way that the rest of the firearm is unaffected. :neener:

The reason I mentioned disappear is because I was wondering what would happen in the event of the worst case scenario of a catastrophic sear failure.

[rcmodel]

If the sear "magically disappears", the hammer *Intercept Notch will not function. Because the sear is what catches it.

*Not a Safety notch, Not a half-Cock notch.

It is the Intercept Notch, and it is only there to catch the hammer if it slips during thumb cocking, or slips off the sear during normal operation due to a defective hammer, sear, or sear spring.

rcmodel

[krs]

Anything is possible in the movies and computer games, but I'd like to know where the "1/4 cock/safety notch" is too.

I know of the sear interrupt position on a hammer, but it's designed for the sear to 'half cock' in, but of course the sear has disapeared so that's not gonna' happen.

If an airplane in takeoff power is on a treadmill which is running under nose to tail will the airplane take off? Or something like that. We can pretend...:rolleyes:

[FullEffect1911]

If an airplane in takeoff power is on a treadmill which is running under nose to tail will the airplane take off?

There is no air moving over the wings, so there is no lift and therefore no take off. But the plane is getting a good workout. :D


It is the Intercept Notch

Your right, I used the wrong term.


But the fact of the matter is if the sear disappeared with the safety in the on position, the hammer would fall as if the trigger was pulled.


This question is just academic.

[frogomatic]

the thumb safety is a trigger block, and the grip safety is a sear block. Neither block the hammer, so if the sear suddenly dissapeared, it's going bang.

[krs]

Other way around, frogomatic.

(Is a "Frogomatic" something to use in the kitchen in cooking for puree'd frog?)

[rcmodel]

If an airplane in takeoff power is on a treadmill which is running under nose to tail will the airplane take off? Of course it will!

Airplanes are not wheel driven.
They are propeller or jet engine driven.

What the runway under them is doing has no effect on the drive system.

rcmodel

[nitetrane98]

The 1/4 cock reference could possibly be the Series 80 Colt which catches at just off the firing pin. (actually, it seems, somewhat less than 1/4) The hammer will fall when the trigger is pulled but with insufficient power to strike a primer. Of course earlier models should preclude the hammer falling at all at half cock when the trigger is pulled.

[Claude Clay]

is there a reason you have not tried it on a gun of your own??

[FullEffect1911]

The 1/4 cock reference could possibly be the Series 80 Colt which catches at just off the firing pin.

thank you for that.


Quote:
If an airplane in takeoff power is on a treadmill which is running under nose to tail will the airplane take off?
Of course it will!

Horribly OT but,

If the airplane is on a treadmill and assuming the threadmill is matching the thrust from the prop or turbines the airplane would be stationary. Just like a human running on a treadmill. As long as the plane is stationary it is not getting air rushing over the wings and therefore no lift and no takeoff.

I'm not positive these are the assumptions that were proposed, but that's how I took the question.

[FullEffect1911]

is there a reason you have not tried it on a gun of your own??

What removing the sear? I suppose I could do that, but I got lazy and didn't want to disassemble the gun. I was reasonably sure that the answer was the hammer will fall as if fired, and wanted to find out if that was in fact the answer.

Now conversely if i had the power to alter time and space and just make the sear disappear... but alas, I just haven't developed the technology as of yet. :D

[rcmodel]

Think about it!

A running human is propelled by his feet on the treadmill.

An airplane is propelled by the propeller, which could care less what it's feet, or wheels are doing.

Airplane wheels are free-wheeling, and could be turning 300 MPH the wrong way under the plane without making one bit of differance to the prop thrust.

Can a seaplane take off in a fast running river?
Of course it can.

rcmodel

[nitetrane98]

Prop thrust over the wings is insufficient to lift a plane into the air. If that were case, a full power runup before takeoff would lift the plane into the air. If a plane cannot gain enough forward momentum to produce the little black arrows (the ones in all of the pictures) that lift a plane off the ground it ain't going to fly.

[FullEffect1911]

And i'll have you know this topic now started a discussion with my brother... we are both engineers and he agrees with you RCmodel...

Edit:
Darn it, why can't i ever be right... RC model wins. http://mythbustersresults.com/episode97

[rcmodel]

Again, there is no thrust to the wheels, so it doesn't matter if the runway is a treadmill under it.

A plane can't take off setting still, so no, a full run-up with the brakes on & wheels chocked won't make it fly because it is unable to move forward through the air and create lift.

But if the wheels can turn, there is not even 1/10,000,000 of one percent as much wheel bearing friction as there is prop thrust working against it.

Even if the treadmill where running a thousand miles an hour under the plane, the prop thrust would way more then overpower the wheel bearing friction.

rcmodel

[FullEffect1911]

Again, there is no thrust to the wheels, so it doesn't matter if the runway is a treadmill under it.

A plane can't take off setting still, so no, a full run-up with the brakes on & wheels chocked won't make it fly because it is unable to move forward through the air and create lift.

But if the wheels can turn, there is not even 1/10,000,000 of one percent as much wheel bearing friction as there is prop thrust working against it.

Even if the treadmill where running a thousand miles an hour under the plane, the prop thrust would way more then overpower the wheel bearing friction.

rcmodel

Absolutely correct, the thrust from props and turbines is imparted on the air, not on the runway. All you need to get over is bearing friction.

I got rid of most of my post because, well, i was wrong. I didn't want more misinformation out there on my behalf.

This may have been one of the most friendly arguments in internet forum history. :D

[rcmodel]

Don't feel bad.
A lot of folks have a very hard time wrapping their head around this one! :D

The real pilot on Mythbusters didn't even think his plane could take off on a treadmill, or tarp moving under his plane.

rcmodel

[FullEffect1911]

yeah but i should have known better, I'm mentally slapping myself for this one. :o

If what i was saying were true, space shuttles out in space wouldn't be able to move.

[Jolly Rogers]

Hammer will be impeded but will drop... Look here:
http://www.thehighroad.org/showthread.php?t=231096
See the large half moon cut in the hammer body?
The main lug body on the thumb safety will impede the hammer rotation when the lug contacts the cutout. Assuming the thumb safety is in the safe position.
Same thing a different way...Can you remove the thumb safety from the weapon with the hammer down?? No clearance. Hammer must be cocked.
Joe

[nitetrane98]

Count me as one having a hard time getting my head around it. It comes in little flashes, but then vaporizes.
Kudos RC

[FullEffect1911]

Hammer will be impeded but will drop... Look here:
http://www.thehighroad.org/showthread.php?t=231096
See the large half moon cut in the hammer body?
The main lug body on the thumb safety will impede the hammer rotation when the lug contacts the cutout. Assuming the thumb safety is in the safe position.
Same thing a different way...Can you remove the thumb safety from the weapon with the hammer down?? No clearance. Hammer must be cocked.
Joe

Excellent find, thank you Jolly Rogers. Slows but won't necessarily stop, interesting.

I do have another Question though, I have a series 80 hammer on my Springfield. There seems to be three positions the hammer will stop on when I pull it back slowly from rest.

The first position is very close to the firing pin and will drop when the trigger is pulled. The second is a little bit further back but doesn't seem to be able to drop when the trigger is pulled (though it may with proper force). And the third position is of course the hammer hooks.

Are these first two positions just different spots in the series 80 intercept notch (half cock notch)?

[krs]

rcmodel knows little about seaplanes....:)

There was a downloadable working model of a 1911, sort of the "Visible Man" of a pistol in which the sear could be removed from view and other parts could be made invisible or transparent as the pistol cycled. I thought it was put together by STI but caan't find a link to it anymore. someone know what I'm talking about?

[nitetrane98]

Hmmm, maybe a SA thing. My Colt Series 80 doesn't have the 1/2 notch. But I did find with the slide removed it is indeed close to 1/4 hammer travel.

[FullEffect1911]

Hmmm, maybe a SA thing.

yep, it is.

Apparently it actually shows a picture of this in the Springfield instructions on page 11. Why does everyone need to be unique.

[Jim K]

Leaving seaplanes aside, if the sear of a standard 1911 is removed (magically or the old fashioned way), and the safety engaged, the hammer will NOT be kept from falling, but it will push the safety out of the way which will slow it somewhat.

How do I know? Well, unlike the theoretical folks who argue about it, I tried it.

Note that on some Spanish and other 1911 "not quite clones" the safety is made to block the hammer and raise it off the sear rather than blocking the sear. In those guns, the safety will keep the hammer from falling if the sear "disappears".

Jim

[Master Blaster]

If the gun is an 80 series, the hammer will be stopped by the firing pin block, which will stop the firing pin from moving forward, so with the 80 series even if the sear disappears or fails completely, there will be no AD.

With a 70 series gun, with no firing pin block there will be a boom if the gun is loaded. But if you use a holster with a thumb strap for cocked and locked carry, then the hammer on the 70 series will be stopped by the strap.

[FullEffect1911]

With a 70 series gun, with no firing pin block there will be a boom if the gun is loaded. But if you use a holster with a thumb strap for cocked and locked carry, then the hammer on the 70 series will be stopped by the strap.

Though I'm pretty darn sure the odds of such a catastrophic sear failure aren't very high, I completely agree with your assessment. Murphy happens, and the holster I have already has a thumb break.

I love it when things work out.

[1911Tuner]

Several years ago, I used a USGI Colt and a badly worn hammer and sear to do a demo for a friend who remained unconvinced of the 1911's function.

All tests included an empty, primed case in the chamber in order to give a loud, clear signal that the system had failed.

First, I ground a full 1/8th inch off the sear crown, leaving a squarish profile...to simulate a failed sear.

Not only did the hammer hold full cock...it actually fired and functioned normally for a couple magazines before the hammer started to follow the slide. The half-cock never failed to grab the hammer. (Sorry, rc...It's just easier to type half-cock.)

Next, I removed the hammer hooks completely...thumbed the hammer back and held it...engaged the safety, and let go of the hammer.

The half-cock stopped it cold.

Next...I ground the half-cock notch off, leaving a rough nub to simulate a completely failed notch...held the hammer, and engaged the safety...and turned it loose.

The hammer pushed the safety to the OFF position, and fell to the slide.

It required about 3 dozen repeats before the primer fired...likely as the altered sear wore the nub of a half-cock smooth and let the hammer fall with enough force to light it off.

You may draw your own conclusions...

[nitetrane98]

Ah yes, Mr. Murphy. But several corrolaries will preclude him from showing up while the gun is holstered. Rule #1 is the only sure way to keep Murphy at bay. Hey that rhymes!!!

[FullEffect1911]

You may draw your own conclusions...

I agree with you tuner, it sounds like a snowball's chance in the warmest layer of hell... but... but.... i already have the darn holster and it's comfy :D

Though you experiment does speak volumes, thank you once again.



Rule #1 is the only sure way to keep Murphy at bay. Hey that rhymes!!!

I agree completely, but I still wouldn't want any firearm going off in my trousers under just about any circumstances.

[Jim K]

Hi, 1911 Tuner,

Your conclusion is correct, but the hammer is slowed by the bottom surface contacting the safety stud and pushing the safety down. Ultimately it is the safety spring and plunger that slows the hammer down, not the sear (not there in this scenario) rubbing on the hammer face.

Jim

[1911Tuner]

but the hammer is slowed by the bottom surface contacting the safety stud and pushing the safety down.

That didn't slow it much, Jim...especially not after I finished grinding off the rough protrusion where the half-cock once was. (I didn't completely remove it at first. I left a little of it to simulate a broken half-cock notch, since they rarely ever completely shear off flush with tha hammer.) The sear still resets, and any sort of "speed bump" that it encounters on the hammer face tends to slow things down. If you've got an old hammer that you don't mind destroying...play with it and you'll see what I mean.

As you saw when you removed the sear...the hammer wipes off the safety almost like it isn't there.

[Jim K]

I didn't try with a primed case (getting late and wife is in bed) so I am not sure if the hammer is slowed enough to keep the gun from firing.

Anyway, I am glad that sears can't just go "poof" and vanish.

Jim

[1911Tuner]

I didn't try with a primed case, so I am not sure if the hammer is slowed enough to keep the gun from firing.

Unless the safety detent is super-stiff...it won't. Back in the 80s, I had a guy show me a 1918 GI Colt that had a non-functional thumb safety. The lug had cracked, and it would let the sear move away from the hooks far enough to escape, releasing the hammer. As it fell, it would wipe the safety off and fire as though it was never engaged.
Close examination showed that the sear moving wasn't causing the safety to drop. It was completely due the hammer falling on it.

I fitted another safety to the gun, and he was happy.

[Walkalong]

Theoretically, it will catch in the 1/4 cock/safety notch. In general it works pretty well as long as the trigger is not pulled. It is there in case the hammer slips from under your thumb or the sear/hammer engagement fails.OK, 1/2 cock or interceptor notch, even if the hammer is 3/4 of the way down. :D