Don't drop slide or will ruin sear?

[Banzai]

In reference to 1911 pistol, I've heard all sorts of things. Will dropping the slide on an empty chamber ruin the sear? How, then, do you return the slide to battery if the chamber is empty, or are you doomed to forever having a locked back slide when storing a 1911?
And just what does "..dropping the slide.." mean? Is this allowing it to slam home, or any action that returns the slide to the foremost position?
I know that this may seem like a battle of syntax, but in investigating a few smiths locally, all of them waranted their action jobs "...until some knucklehead drops the slide on an empty chamber..", and none of the 3 could agree on just what their definitions were!!
Some one please set me straight here!



Tom



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A "Miss" is the ultimate overpenetration!
You can never be too rich, too skinny, or too well armed!

[Robb]

I've heard this too. To keep from harming the sear or to keep from having a 'slam-fire', 1. hold the trigger to the rear when letting the slide go home (I don't like this because I believe your finger shouldn't touch the trigger UNTIL you are ready to fire). 2. With you weak thumb hold the hammer down when allowing the slide to slam home or when chambering a round (this kinda makes it a 'target' gun only, if the trigger is that fragile I don't care to own it).
Robb

[This message has been edited by Robb (edited May 19, 2000).]

[Mike Baugh]

Dropping the slide on an empty chamber is said to create hammer bounce which is hard on the polished engagement surfaces of the sear and hammer , the theory is a cartridge in the chamber will buffer this during firing [the slide shuts against brass instead of steel to steel , thus reducing the shock]. To return the slide to battery with an empty chamber simply pull the slide back with the mag removed and the slide release will drop and the slide can be eased forward , or depress the slide release while holding the slide and ease the slide forward . To me "dropping the slide" means hitting the slide release and letting the slide slam shut on an empty chamber . Good luck , Mike...

[George Stringer]

Banzai, dropping the slide on an empty chamber isn't good for anything. I can't really say that it causes any problems with the sear or hammer. The part that is most affected is the extractor. It's the quickest way to kill one. George

[bk40]

My 'smith told me to never drop the slide on an empty chamber (1911). Don't know if their is any truth to this or not, but he told me you get 3 chances at this... 3rd time screws up a fine tuned trigger job. His source of the 3 drops as from Bill Wilson.
All the above applies to letting the slide slam home. Guiding it shut by hand is perfectly fine.

[James K]

As far as damaging the sear is concerned, it doesn't matter if the chamber is empty or not, or whether you hold the trigger or not. What do the "experts" think happens when the gun is fired? The hammer drops on the sear much faster then than when just releasing the slide.

If the trigger is extremely light, dropping the slide without holding the trigger can allow the hammer to fall and the sear to drop into the half cock notch. The reason is that when the barrel stops on the slide stop pin, and the slide goes into battery, the gun moves forward. The trigger, loose in the frame, tends to remain where it is (see old Isaac about this), and so moves back relative to the frame, thus "pulling itself". This is the reason for light plastic or aluminum triggers in match guns.

Jim

[johnwill]

Here's a direct quote from SM&A, rather well known gunsmiths. These guys have done a number of guns for me, including one of my 1911's. Mac Scott seems to think that allowing the slide to slam on an empty chamber is bad, and I trust his opinion a bunch. You may want to re-think allowing folks to do this to your guns.

"Trigger work is a necessity on any serous definsive 1911 pistol. All trigger jobs guaranteed until "Zippy the Pinhead" lets the slide slam home on an empty chamber. "

[G50AE]

You can drop the slide on an empty chamber and dry fire the pistol as many times as you want. Unless the design is deffective or the gunsmith does not know what he is talking about.

[Art Eatman]

I swanee, I'm gonna write a book: "Problems I've Never Had With A 1911".

The hammer-sear engagement will get a much stronger jolt during recoil than from pressing the slide release.

Some competition trigger-jobs will allow "follow" to the half-cock position when the slide is released to freely return to battery. I fail to see how this can hurt the sear's engagement surface. The movement is slow compared to normal lock time. The mechanism for undue wear is unknown to me--doesn't mean it can't exist, but it sure ain't obvious.

George, how can the extractor be hurt? Does the tip of it actually hit the barrel?

My problem is that I've been doing Bad Things to 1911s for 50 years, and nothing's ever busted or gone bad...

Damfino, Art

[James K]

The extractor should not be harmed by letting a slide drop on an empty chamber, nor should the sear.

When the gun fires, the recoiling slide slams the hammer back, causing it to come away from the slide and bounce off the grip safety. It bounces back until it strikes the bottom of the firing pin tunnel on the slide (look for a dent in that area), then it rides the fast moving slide until the slide bounces off the recoil spring guide and begins moving forward. That bounce gives the slide a much faster forward motion than it ever gets from a manual release. When the slide clears the hammer, the hammer drops hard on the sear. This drop is harder than any that occurs when manually releasing the slide. The "cushioning" of feeding a round has little effect.

Dropping the slide will not harm the hammer, the sear, or any other part of the gun, since the gun takes a far worse beating when being fired. The part that does take a beating is the internal pin part of the slide stop. It has to bring the whole shebang to a screeching halt.

Jim

[Will Beararms]

George Stringer is nuts on. It's a good idea to "ride the slide" on ANY semi-automatic handgun when the chamber is or will be empty (No loaded mag in gun).

It's safe and simple to do and just one more thing you can do to add to the lifespan of your weapon.

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"When guns are outlawed;I will be an outlaw."

[Will Beararms]

One more thing Banzai: anytime I allow anyone to handle a semi-auto I am privileged and blessed to own, I make it clear not to drop the slide on an empty chamber or mag ahead of time.

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"When guns are outlawed;I will be an outlaw."

[skeeter]

Jim Keenan
You are forgetting one thing when you say the slide is reacting far more violently from actual firing than when you just let the slide go with the slide stop. When firing the gun it is recoiling back so that the slide is moving slower relative to the also moving frame. With all due respect to you I think I will take Bill Wilson's advice rather than yours.

[James K]

Hi, Skeeter,

Feel free to take anyone's advice. I will note that many people who know the pistol well from a standpoint of accurizing and working on, don't understand the dynamics of the parts and pieces when actually firing. One well known writer on the pistol doesn't seem to really know how it works, if his book is any indication.

Jim

[johnwill]

I hasten to point out that your generalization that gunsmiths don't know the dynamics of the 1911 seems to fly in the face of logic! How do you come to such a conclusion?

You say: "One well known writer on the pistol doesn't seem to really know how it works, if his book is any indication."

One huge point, let's not confuse gun writers with gunsmiths, there is a world of difference between the two! I'll agree that a significant number of gun writers don't know the muzzle from the magazine, but we're talking about nationally recognized gunsmiths, a totally different breed.

[Art Eatman]

Johnwill, re-read what Jim said. The fact that somebody can stone a sear or do excellent machine work on a pistol does not necessarily mean they fully understand the internal happenings.

Not all gunsmiths are also designers. Lots of guys can build good guns, but have not even a semblance of John Browning's understanding of the inter-relationships of the mechanism.

Similarly, I've known a lot of guys who could do good work in building a race-motor, but could not begin to understand a conversation about the effects of advancing or retarding the cam-timing. Or explain how to calculate the length of individual exhaust header-pipes, tuned for best extraction at some certain rpm-range.

No big deal, but Jim's statement is accurate.

, Art

[johnwill]

I still will take the word of virtually all major gunsmiths that dropping the slide on an empty chamber will damage a match tuned trigger job over a casual comment in this forum.

[Will Beararms]

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"When guns are outlawed;I will be an outlaw."

[James K]

Hi, Johnwill,

Just for fun, ask the gunsmiths what causes the Browning 1911 type pistol to function.

Will it work if the barrel is blocked and the bullet can't move?

Jim

[johnwill]

I can't see the "fun" in this, if you really want to know how the 1911 functions, I'd suggest Kuhnhausen's fine pair of books on the 1911. As for what this has to do with the topic at hand, I have no idea.

[James K]

Isn't he the fellow who says the bullet exits the barrel and the pressure drops to zero before the action begins to open? His pistol may work that way, mine doesn't.

Jim

[johnwill]

OK, let's make sure I understand you. You know more than Jerry Kuhnhausen about the 1911? It's odd that I never hear your name mentioned when people talk about 1911 experts.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Isn't he the fellow who says the bullet exits the barrel and the pressure drops to zero before the action begins to open? His pistol may work that way, mine doesn't.[/quote]

Actually, he says the barrel and slide don't unlock until the bullet leaves the barrel. I'd be a bit surprised if your slide moves enough to unlock the barrel/slide before the bullet leaves the barrel. Are you sure your gun is really a 1911?

[James K]

Golly, Johnwill, I think it is a 1911, but I could be wrong, being so ignorant.

Kuhnhausen is very good at working on 1911 type pistols and his books are invaluable to anyone, myself included.

But the other JK shows a pistol with the bullet leaving the barrel (Fig. 30 in my Vol. 2) and says that bullet exit drops the pressure to zero. This is not true, there is still some residual pressure, but let that go for a moment. At that point, he shows the barrel and slide fully locked and in battery.

In fact, the barrel and slide, locked together, begin to move at the same instant the bullet does. The forward motion of the bullet (not gas pressure) produces the equal and opposite reaction of moving the barrel-slide unit backward. The barrel-slide unit is more massive and does not move as fast as the bullet but it does begin to move at that time. Backward pressure on the cartridge case is not a factor, because it is pushing against the slide, which is immovable relative to the barrel at this point.

The barrel-slide unit picks up momentum as the bullet moves down the barrel and when the bullet exits has already begun to unlock.

The momentum carries the barrel and slide back until the barrel drops and unlocks fully from the slide, at which time the slide retains enough momentum to complete compression of the recoil spring, cock the hammer, and prepare to feed another round.

The slide is not propelled forward only by the energy stored in the recoil spring, but also by some of its backward momentum stored when it impacts and bounces off the recoil spring guide. This results in the slide moving forward after firing much faster than it would move under spring energy alone, which gets us back to the question of the rapidity with which the hammer drops on the sear.

Note that it is not (contrary to Fig. 29) the gas pressure itself that causes the pistol to function, it is the motion of the bullet.

In a recoil operated pistol (unlike a blowback) nothing will happen unless the bullet moves. This can be proven (and has been) by plugging up the barrel, leaving just enough room for the cartridge, and then firing the gun. The bullet can't move and the gun will not open. The gas pressure will leak out over time, but the gun will stay locked.

That is the difference between a recoil operated pistol (whether Browning type or another design) and a blowback pistol, where the operation is done solely by gas pressure. Blocking the barrel on a blowback pistol is not recommended.

As to my "fame" or lack of it, my inherent modesty precludes comment.

HTH

Jim

[Bimjo]

Jim,

Not to pour fuel on a potential fire, but I'm trying to understand the physics (okay, I flunked it) here.

Wouldn't the action of stripping a new round from the magazine and then chambering the new round bleed off/negate the rebound speed of the slide that you mention?

If so, isn't it possible that the slide would then be moving more slowly than one dropped from locked back position by spring pressure alone (assuming an empty chamber/no round to feed)?

It seems that dropping the slide on a empty chamber results in a faster movement than chambering a round from the mag with the slide locked back. Obviously I can't actually see a difference, but the perception of feel and hearing is that this is so.

If the slide is actually moving more slowing chambering a round, then my (probably faulty) logic makes me think that the stress on the hammer/sear interface could also be less.

Unless of course you were speaking about the slide closing on an empty chamber in both instances, in which case this entire post has been a big waste of bandwidth.

Then again, with a hammer/sear interface set to Mr. Browning's specs, I kinda doubt it'll make much difference anyway.

Bimjo (ramblin' again)

[James K]

Hi, Bimjo,

Yes, the action of picking up a round from the magazine slows down the slide in its forward motion, whether it is running forward after firing or just released by hand.

We all got a bit off the track on this one.
The hammer full cock notch drops on the sear when the slide moves out of the way. This action is the same regardless of whether the slide is dropping on an empty chamber or not, whether the gun has just fired or not. If the sear or hammer is damaged in one case, it will be damaged in any case.

But, with a very light trigger pull, another factor comes into play. When the slide is dropped, the barrel impacting on the slide stop pin brings the whole moving barrel-slide mass to a quick halt and jars the whole gun forward.

The 1911 trigger is free floating in the frame, so when the gun is jarred forward, the trigger tends to remain in place, moving rearward in respect to the frame. So in effect the trigger pulls itself. If the sear-hammer interface is not properly set up, the hammer will drop on the half cock notch. This will not normally damage a properly hardened and set up sear and hammer, but can damage an overly delicate one. (This does not happen in firing, because the trigger is being held to the rear.) This is the origin of the idea that dropping the slide is bad.

Obviously one can get around this by easing the slide down, or by holding back the trigger or hammer when releasing the slide. Other solutions, such as lightweight triggers (plastic or aluminum) can minimize the condition, which is the result of smiths going along with customer demand for ever lighter trigger pulls in what was intended as a military pistol.

I am not against easing the slide down. I am still saying that in a normal 1911 type pistol, there is no need to do so.

Jim