Safeties...how do they work?

[Soginator]

Long story short, I got into a debate with someone about carrying a 1911 cocked and locked, saying that there are two safeties blah blah. I'm sure most of you heard this. What I am wondering is how the safeties work if the trigger is pressed or the hammer dropped.

Same question, but for Glocks why is the trigger considered safer?

[350skylark]

The grip safety blocks the trigger bow from contacting the sea/dissconect. The thumb safety blocks the sear from being able to move at all. A series 80 1911 has a firing pin safety that won't let the firing pin move forward unless the tigger is pulled

[PyroFox79]

Magic?

[350skylark]

As far as the glock, it has 3 internal safteys. The res all kinds of videos explaining them and how they work. As for being safer? Ymmv

[Cokebottle]

1911:
Grip safety blocks trigger from being pulled, some also include a firing pin block. Thumb safety blocks seer.

Glock/M&P:
Trigger safety physically blocks trigger from being pulled by drop or object in trigger that does not also press the safety. Striker safety blocks striker movement. Both safeties are automatically released when the trigger is pulled. XD adds a grip safety, but the mechanism is very similar to Glock/M&P.

Beretta 92 and similar:
Decocker, firing pin is 3-pieces, center piece is rotated out of alignment with the front and rear, hammer is released, trigger disengaged.

Revolver:
Modern revolvers with exposed hammers have a transfer bar safety. The hammer itself has a "shelf" at the top that impacts the rear of the frame above the firing pin. The shelf is just deep enough to prevent contact with the pin.
When the trigger is pulled, it pushes a bar up in front of the hammer that fills in the area below the shelf. The hammer pushes the transfer bar into the firing pin. Since the transfer bar is not raised unless the trigger is pulled, the hammer can "rest" on a live chamber without danger of discharge should something impact the hammer.
If the trigger is released before the hammer impacts the pin (manually lowering the hammer) the transfer bar drops out of the way and the hammer can rest on the frame.
Shrouded hammered revolvers often do not have a transfer bar, but the hammer can not be impacted by an external force, and the pin is small/light enough that there is negligible risk of discharge from external impact to the frame.


The striker design is a tradeoff. Because there is no manual safety, an accidental trigger pull will discharge, much like a DA revolver (but without the 10lb pull). Mechanically though, if the gun is dropped, the firing pin is blocked from moving forward and contacting the primer.
This would be an extremely rare and unlikely situation for any modern gun. Some older 1911 models with a heavy firing pin would tend to discharge if the gun was dropped on the muzzle or impacted with enough force to jar the pin as if the hammer had hit it.

[baggss]

1911:
Grip safety blocks trigger from being pulled, some also include a firing pin block. Thumb safety blocks seer.

Glock/M&P:
Trigger safety physically blocks trigger from being pulled by drop or object in trigger that does not also press the safety. Striker safety blocks striker movement. Both safeties are automatically released when the trigger is pulled. XD adds a grip safety, but the mechanism is very similar to Glock/M&P.

Beretta 92 and similar:
Decocker, firing pin is 3-pieces, center piece is rotated out of alignment with the front and rear, hammer is released, trigger disengaged.

Revolver:
Modern revolvers with exposed hammers have a transfer bar safety. The hammer itself has a "shelf" at the top that impacts the rear of the frame above the firing pin. The shelf is just deep enough to prevent contact with the pin.
When the trigger is pulled, it pushes a bar up in front of the hammer that fills in the area below the shelf. The hammer pushes the transfer bar into the firing pin. Since the transfer bar is not raised unless the trigger is pulled, the hammer can "rest" on a live chamber without danger of discharge should something impact the hammer.
If the trigger is released before the hammer impacts the pin (manually lowering the hammer) the transfer bar drops out of the way and the hammer can rest on the frame.
Shrouded hammered revolvers often do not have a transfer bar, but the hammer can not be impacted by an external force, and the pin is small/light enough that there is negligible risk of discharge from external impact to the frame.


The striker design is a tradeoff. Because there is no manual safety, an accidental trigger pull will discharge, much like a DA revolver (but without the 10lb pull). Mechanically though, if the gun is dropped, the firing pin is blocked from moving forward and contacting the primer.
This would be an extremely rare and unlikely situation for any modern gun. Some older 1911 models with a heavy firing pin would tend to discharge if the gun was dropped on the muzzle or impacted with enough force to jar the pin as if the hammer had hit it.

Great info Cokebottle, Thanks!

[Soginator]

1911:
Grip safety blocks trigger from being pulled, some also include a firing pin block. Thumb safety blocks seer.

Glock/M&P:
Trigger safety physically blocks trigger from being pulled by drop or object in trigger that does not also press the safety. Striker safety blocks striker movement. Both safeties are automatically released when the trigger is pulled. XD adds a grip safety, but the mechanism is very similar to Glock/M&P.

Beretta 92 and similar:
Decocker, firing pin is 3-pieces, center piece is rotated out of alignment with the front and rear, hammer is released, trigger disengaged.

Revolver:
Modern revolvers with exposed hammers have a transfer bar safety. The hammer itself has a "shelf" at the top that impacts the rear of the frame above the firing pin. The shelf is just deep enough to prevent contact with the pin.
When the trigger is pulled, it pushes a bar up in front of the hammer that fills in the area below the shelf. The hammer pushes the transfer bar into the firing pin. Since the transfer bar is not raised unless the trigger is pulled, the hammer can "rest" on a live chamber without danger of discharge should something impact the hammer.
If the trigger is released before the hammer impacts the pin (manually lowering the hammer) the transfer bar drops out of the way and the hammer can rest on the frame.
Shrouded hammered revolvers often do not have a transfer bar, but the hammer can not be impacted by an external force, and the pin is small/light enough that there is negligible risk of discharge from external impact to the frame.


The striker design is a tradeoff. Because there is no manual safety, an accidental trigger pull will discharge, much like a DA revolver (but without the 10lb pull). Mechanically though, if the gun is dropped, the firing pin is blocked from moving forward and contacting the primer.
This would be an extremely rare and unlikely situation for any modern gun. Some older 1911 models with a heavy firing pin would tend to discharge if the gun was dropped on the muzzle or impacted with enough force to jar the pin as if the hammer had hit it.

I appreciate the detailed answer. Thank you!

[Soginator]

Follow up question. I leave my EMP loaded because I see no reason to constantly unload it. Am I risking anything by leaving the hammer cocked for a month at a time?

[Killer Bee]

good article on springs

read this reposted article from American Handgunner '03

Magazine spring madness: 'creep' to your 'elastic limit' to un-earth the urban legend of 'spring-set'

American Handgunner
May-June, 2003
by John S. Layman


The shooting sports are full of some of the most knowledgeable and capable people you'll meet anywhere. I've been impressed consistently with the abilities of those I meet at the range to diagnose and fix a gun problem with as little as some spray lube and a cotton swab. However, sometimes a myth will creep into the folklore.

The magazine spring myth has been around for many years and is growing in popularity. It goes something like this: "You should unload your magazines when they're not in use or the spring will weaken causing failures to feed." This has gone as far as shooting competitors actually unloading their magazines between stages to extend the life of their springs. A variant of this myth is: "You should never load a magazine to capacity and should always leave it one round short." What if you need that round some day?

Recently, I read an article in a gun magazine suggesting you rotate your magazines so the ones not in use can "recover and rest." The same author uses the phrase "spring-set" to describe weakness of a spring because it was compressed for a long time. Hogwash. There's nothing further from the truth. Springs don't care how long they're compressed and don't require rest, recreation or even a vacation from time to time.

Shameful Spring Benders

To put this one to rest, you have to understand creep. Creep is the slow flow of a non-ferric metal like copper, brass and lead under force. At temperatures outside of a furnace, steel doesn't have any appreciable creep. Under most conditions, steel flexes and then returns to its original shape. When pushed past its elastic limit, steel will bend and not return to its original shape. All designers of well-made magazines make sure the spring never approaches the elastic limit when the magazine is fully loaded. Honest. This means the spring will not weaken when the magazine is fully loaded -- not even over an extended time. Like 50 years. American Handgunner recently ran a story about a magazine full of .45 ACP that had been sitting since WWII and it ran just fine on the first try. So there you go.

Now that the light of truth is leaking out, lets talk about what is causing failures to feed. The only way to weaken a magazine spring is to flex it past its normal range (elastic limit). If this is happening, somebody is trying to overload a magazine or has "adjusted" it by bending the spring. Both of these could cause feed failures. Shame on you if you're a spring bender.

Carlton Nether, Customer Service for Beretta USA, tells us keeping a pistol magazine loaded for an extended period doesn't cause magazine spring failure, however, failures to feed can result. He says, "The ammo will 'roll' in the magazine. If the mags are kept loaded and moved around a lot -- say on a cop's belt -- the rolling action can, over time, cause creases in the cases. These creases can cause malfunctions. Also the top bullet will roll against the magazine lips and creasing can occur there as well. Just check old ammo that's been bouncing around in a magazine for a long time.

We tell police officers if they keep loaded magazines, take a few seconds to "cycle" the ammo. Periodically unload the mag and reload it in a different sequence. This movement will allow the bullets to be in different parts of the magazine and help eliminate creasing.

At STI, Dave Skinner, President and CEO says, "Personally, I rotate my 'under the bed' and 'under the seat' mags about every six months. I always empty them the 'fun' way and have never had a failure." Given what we learned above, this sounds like a good idea. Smith and Wesson customer service also says magazines can stay loaded indefinitely without hurting the spring.

As we add force onto a spring, it will displace the same amount for each amount of force we add. This is true until the spring passes a certain point called the elastic limit. Robert Hooke discovered this theory back in 1660. Hooke's Law states: "If the applied forces on a body are not too large, the deformations resulting are directly proportional to the forces producing them." Which means, in actual human being language, if we load a spring past its elastic limit, it permanently deforms. It still provides a force against the load but the force is no longer proportional. If this happens, when we unload the spring (such as when we empty a magazine that has been over-loaded) the spring never returns to a state where it can provide the same load for the same amount of displacement.

Trust Us

When a magazine manufacturer designs a spring, they plan for a preload. The spring is already compressed some in the magazine. On the curve below, this would be Point A. The spring compression would be designed to be below the Elastic Limit. When fully compressed, the spring would be at Point B. If the spring is ever compressed past the elastic limit, say to Point C, it won't ever behave the same. Like a recalcitrant lazy Uncle, it will have a lower spring force for each amount of displacement. On the drawing, the spring would now cycle between points D and E. This means that -- particularly with the last bullet or two -- the force pushing the bullet up would be less and lo-and-behold, a mis-feed might occur.

When somebody stretches your spring to "fix" your magazine, they are trying to get you back on the original curve. They may get pretty close, however, it's unlikely the spring will ever perform to its original design. The elastic limit is now shifted lower and your magazine spring may fail to perform fairly quickly.

Having said all this, if you have a magazine that isn't feeding right, what should you do? First, disassemble the magazine and clean it thoroughly. Then try it with new, factory ammunition in a freshly cleaned gun. This takes away some of the possible causes. If you are still having feed problems, send it back. Even the low cost, after-market magazine manufacturers will fix the problem at no cost to you other than shipping. If it's a magazine from the gun's manufacturer, let them troubleshoot and repair the problem. Otherwise, toss the mag. It's not worth risking your life to save a few bucks. And that's the truth.

RELATED ARTICLE: Definitions

Creep: The flow or plastic deformation of metals held for long periods of time at stresses lower than the normal yield strength.

Elastic Limit: The maximum stress that material will stand before permanent deformation occurs.

Yield Strength: The stress at which the metal changes from elastic to plastic in behavior, i.e., takes a permanent set.

Permanent Set: Non-elastic or plastic, deformation of metal under stress, after passing the elastic limit.

Magazine Recommendations

* Clean your magazines when they get gritty. Apply oil then remove all excess. Oil attracts dirt that may cause malfunction.

* If you find rust on the spring, this is culprit. Rust changes the thickness of the metal and reduces the force applied to the follower. Cleaning off the rust may help. For a gun you depend on, replace the spring. All the major brands and most of the smaller ones have replacement mag springs available or try Wolff Springs.

* If you keep a magazine loaded for long periods, rotate the rounds every few months. If you carry a pistol on the job or in your car, cycle the ammo frequently. These actions prevent creases from forming which may cause a misfeed.

* If you experience feed problems, first clean your magazines and weapon. Fire a couple magazines of new factory ammo to see if this resolves the problem. If not send the magazine back to the manufacturer -- or toss it.

[Killer Bee]

and lots of threads over in 1911 forum regarding guns cocked for very long periods of time..

[Mitch]

Long story short, I got into a debate with someone about carrying a 1911 cocked and locked, saying that there are two safeties blah blah. I'm sure most of you heard this. What I am wondering is how the safeties work if the trigger is pressed or the hammer dropped.

Same question, but for Glocks why is the trigger considered safer?

Other guys gave you detailed replies, but here's a more general one:

The energy in a firearm is stored in the hammer or striker spring. When the hammer or striker is cocked, there is energy stored in the spring that is trying to push the firing pin forward. It is held back by the sear, safety, whatever. These are mechanical devices to contain the energy of the spring. They can wear, they can be bumped out of place, they can be poorly designed in the first place.

With a Glock or double action pistol or revolver, the energy to fire the gun is provided by the trigger finger. There is no stored energy in the weapon that can accidentally be released.

This is fundamentally why a Glock would be considered safer than a cocked single action pistol. Has nothing really to do with the safety mechanisms, the fact is, a double action handgun cannot be fired without a finger or some other outside force acting on the trigger. You can't say that about a cocked single action pistol.

There have been many accidental shootings over the years, mostly with rifles, due to improperly designed or modified trigger assemblies. Almost all these incidents have this in common: the weapon was cocked and the owner was relying on the mechanical safety or sear to hold back the energy of the striker or hammer spring.

[Jeepergeo]

There have been many accidental shootings over the years, mostly with rifles, due to improperly designed or modified trigger assemblies. Almost all these incidents have this in common: the weapon was cocked and the owner was relying on the mechanical safety or sear to hold back the energy of the striker or hammer spring.

AND, because the fundamental rule, to keep the muzzle pointed in a safe direction, is ignored for a critical second or more.

Had that basic safery rule been followed, these tragedies would have been avoided.