Safe way for checking hammer follow...

[JeffC]

I've always done this to check for hammer follow, take one thumb and hold down the grip safety and take the other thumb and flick the hammer. Before a range trip today I check one of my guns by flicking it and the hammer follows.... it had a light pull so I was always prepared for this....

So I look and the sear looks like crap (springfield MIM) and I put a new edge on it. Trigger pull is a tick heavy but manageable so I flick it several times and it follows again and the pull becomes light again , So I follow the above steps and the same happens again.... WTH?

Am I doing the sear harm by flicking it or do I just have a soft POS sear?

I've swapped it with one from the parts bin (another Springfield MIM) and I'm afraid to go "flick" testing it to much.

Should I not flick it at all? Is this an unfair test for hammer follow? I don't believe in dropping the slide if I don't have to.....

 

[1911Tuner]

Ban the Flick

Howdy Jeff,

Flick your Bic...Not your hammer.

When you do that, the sear and the hooks crash into each other and do some damage...probably to both. When the slide recoils on a 1911, the hammer overcocks, and falls back to rest on the sear, but the dynamics aren't the same. For one...The hammer initially rebounds against the
underside of the slide instead of falling directly onto the hooks. When the
slide moves forward, the hammer is lowered onto the hooks a lot slower
and more gradually rather than falling with the full force of the mainspring driving it.

Bad news bro...You're probably gonna need a new hammer and sear.

 

[JeffC]

Go figure.....

Okay I won't flick then.... I just answered Jims post on the other forum and he said it would be okay.... I understand that soft parts will beat themselves up but was hoping a good temperd part would stand up to the flicking.

Thanks for the input Johnny

 

[1911Tuner]

My Friend Flicka

Jeff,

One flick as a test wouldn't likely hurt anything. Doin' it before every range session is where the harm lies...Like slammin' the slide home on empty. The damage is cumulative.

Most of the time, hammer followdown is caused by the trigger anyway...or a combination of the trigger and a weak or light mainspring letting the hammer
lose full contact with the sear for a nanosecond. The ones that are caused by bad hook to sear engagement usually let ya know by belchin' loudly.

 

[JeffC]

LOL, I'm tryin' to avoid belchin' in public.....

 

[Old Fuff]

If the hooks on the hammer haven't been excessively shortened, and the pull is set somewhere between 4 1/2 to 6 pounds it's unlikely you will have to worry about the hammer following down. Usually when someone tells me they have that problem an examination of the lockwork reveals that someone did a trigger pull job without the slightest idea about how to go about it.

 

[bountyhunter]

a good temperd part would stand up to the flicking.

A tempered (I assume you mean hardened) part would chip or shatter when beat on in this fashion for some time. A softer part will just beat up and round over the primary sear face.

Tuner is right, the normal slide motion lowers the hammer more slowly than a "hard drop" of the hammer onto the sear. Even the so called "empty drop" of the slide from lockback onto an empty chamber is frowned upon because the slide velocity gets faster than normal when it does not have to strip a round and push it under the extractor. An empty drop is probably less harmful than hammer dropping, but neither is recommended.

 

[Jim K]

FWIW, I think the amount of damage that can be done by the hammer dropping on the sear from that short a distance is greatly exaggerated. The only time I have seen anything like that cause sear or hammer notch failure is when the parts have been filed through the hardening or were dead soft to begin with. And that only after firing had already caused the hammer to be dropped less gently. I think the idea that the slide, moving forward very fast, slowly eases the hammer down on the sear as light as a feather, is not too realistic. That support is gone pretty quickly, and the hammer suddenly has nothing to keep it back. I haven't measured the force (I am not sure I know how), but I doubt it is a "kind and gentle" touch. If it is, it is the only thing about that gun action that is gentle.

Jim

 

[JeffC]

For good measure I'm going to get a new sear, a good one!

Thanks everyone for you input .

 

[1911Tuner]

A Kinder, Gentler Flick

Howdy Jim. Good to have your input.

Agreed that there's not a thing about the cycle that's gentle. The difference here isn't so much the more gradual drop as it is the much shorter distance
involved...and the attendant reduced momentum...when the slide lets the hammer fall back onto the sear. I remember an old Navy armorer who used to change the angle a little on the hammer face on match pistols to position it even closer to the sear after it rebounded back to the slide. At the time, I wondered why he did it, since I understood that the hammer was slammed back into the grip safety...so it couldn't have been to keep it from over-cocking. I never asked him because he was a salty old cuss, and didn't want to be bothered any of us young'uns...It was several years later when it hit me why he did that...after I ruined a a sear and hammer by doing the same thing that Jeff did...absent-mindedly playing with the gun while watchin' the Owl Show. (Anybody old enough to remember the Owl Show may step to the front of the line. You've earned it! LOL)

Good discussion...Cheers all!

 

[bountyhunter]

I would add that it clearly is the case that when the hammer is coming forward "with the slide", it's velocity when it gets to the sear will be SIGNIFICANTLY slower than if I pull the hammer back and let it fly unrestricted. The slide has a lot of mass, not to mention significant friction along the rails as well as between it and the hammer head. Bottom line, the slide comes to a full stop and reverses direction at the end of the stroke, so it has to begin accelerating forward from that point. At the position where the hammer will be stopped by the sear (not much forward of all the way back), it will not be going nearly as fast as if the hammer was simply free dropped.

 

[brickeyee]

After cutting out the part from the raw stock, it is hardened, then tempered.
Hardening is heating above the design temp for the steel and then quenching. The part wil be very hard but also very brittle. To vreate a more usabel part it is often then tempered (heated to a lower temp and allowed to sloly cool). This preserves some of the hardness but leaves the part less likely to fracture or chip.
Surface hardening can be done by heating to a lower temp and then qenching. By treating the surface during the high heat phase (applied chemicals that dissolve into the hot steel) a hard surface with a ductile core can be obtained. This provides a wear surface that is hard but preserves the ductility needed for repeated shock loading.
Most of the sears I have encontered are surface hardened. If you cut through the hard layer, the material is very soft.

 

[Jim K]

Hi, Bountyhunter,

I think you are assuming something that doesn't happen quite that way.
First, remember that steel has a very high elasticity, as shown by those hanging steel balls that bounce for a long time once started.

If you look at pictures (Kuhnhausen, for example), the slide does appear to move forward impelled only by the spring. Not so in normal operation. The slide comes back at a very fast clip, then bounces hard off the recoil spring guide/frame, so that a good part of the rearward energy imparted to the frame is returned to the slide. (This is why pistols with buffers often have feeding problems - the buffer absorbs a lot of the rearward energy and doesn't return enough to the slide.)

So the forward moving slide is going faster than it would if it were just released and had no driving force except that given it by the recoil spring. In fact, it is moving fast enough that some high speed photos show the hammer simply sitting there with a kind of stupid expression before it realizes the slide is not there any more (sort of like Wil-e Coyote on the cliff), and drops on the sear.

I agree that the hammer in normal operation won't drop as far as it will if "flicked", but it doesn't drop all that gently, either. I will still say that if the "flicking" described harms the hammer or sear, there is something wrong with the parts.

Jim

 

[1911Tuner]

To Flick...or not to Flick

I sense another experiment on the horizon...

What we need is two hammers and sears from the same manufacturer, installed in two different guns. One to be used in the normal fashion, and the other will be flicked until it either gives up the ghost, or proves its mettle. Trigger pull to be checked every 100 flicks to see if anything is changing. At 1,000 rounds and 1,000 flicks, the guns torn down and the parts examined.

I'll supply the guns and the ammo if somebody will send me the parts.

Standin' by...

 

[bountyhunter]

I think you are assuming something that doesn't happen quite that way.
First, remember that steel has a very high elasticity, as shown by those hanging steel balls that bounce for a long time once started.
.

Actually, all steel is different based on tensile strength, hardness, density, etc. Steel does have a very limited range if elasticity (engineers call that the range of elastic deformation) which is followed by the "inelastic" deformation from applied stress.... ie, you whack it and it leaves a dent.

As to the characteristics of any given sear? As different as the faces of people on a bus, depends on the part maker What is a fact is that sears need to be very hard to prevent wear on the critical face cuts. A "trick" 1911 will have a primary sear face which is very thin to get a sharp trigger break. That puts a lot of stress on the small area, and if the edge between the primary and secondary cut round over you get hammer follow.

Many sears are surface hardened, most are through hardened by heating and quenching when the steel is made. Expensive sear/hammer sets boast of their high Rc numbers because it translates into longer life for the trigger job.

In any case, sears and hammers tend to be very hard, and that means they are prone to chip and shatter. Chipping is what "flicking" would cause if done for enough time. For the record, it's also what slide dropping on empty would cause.

"I will still say that if the "flicking" described harms the hammer or sear, there is something wrong with the parts."

Actually, I hold the opposite opinion. If the sear is made of steel which is ductile enough to not sustain any damage from repeatedly whacking it, I don't want it in my gun because it isn't hard enough to last as long as I desire.

 

[Jim K]

I happen to believe, and know, that it is perfectly possible to make parts that are hard enough for any reasonable life span without making them so brittle they will chip and break at the slightest provocation. We had reached that level of manufacturing 150 years ago. Only recently have makers junked all that knowledge in the name of cost cutting and "efficiency."

I can't understand how anyone would prefer brittle parts that can break without warning to slightly less hard ones that will wear gradually and detectably.

Jim

 

[bountyhunter]

The need for RC hardness above 50 comes from the fact that bullseye shooters (and also open gun shooters) wanted a 1911 trigger with a sharp "glass rod" break to it. Doing that typically requires a primary sear face that is EXTREMELY thin in physical dimension, so that only a slight trigger movement rotates the sear to the secondary face where the hammer falls. When the surface area is very small, it means the "pressure per square inch" is dramatically increased and the wear on it increases proportionately. The smaller primary face also means that only a slight amount of wear is necessary to remove enough material to get hammer follow.

The original GI sear was immune to just about anything the user could do. But, it also had no relief cut at all so it had a long, heavy pull with serious creep. As you apply the relief cut, which removes contact surface from the sear and hammer hook interface, the drag wear goes up because the pressure is applied over a smaller area. Some tricked out guns have sear face cuts that start to look like the edge of a knife blade, hence the need for higher hardness.