keeping slides locked back?

[Bezoar]

Every time i see news photos or footage taken inside a gun store with semi auto handguns, the slides are always locked back. Just how long is it safe to do so?

At the same time i was thinking that if it was safe to keep it locked back for long times, why not do so? I mean, say you have a semi auto the wife shoots fine, but cant work the slide for some reason? Why not keep that slide locked back for her and have 6 or 7 loaded magazines with it?

 

[wally]

Still need to be able to rack the slide to clear a failure.

If you have room in the safe, I otherwise don't see a problem with storing the gun with the slide locked back.

--wally.

 

[Ala Dan]

I have found that some people that suffer from arthric conditions simply can't
operate the slides on most semi-auto's; and in particular the KEL-TEC's.

Muchless, with .45 ACP's such as the semi-custom guns like Les Baer's TRS
1911. Therefore, as I see it small frame women or persons with a
weakness in their hands probably would feel a bit more comfortable
with a revolver for self defense~!

 

[grendelbane]

I am the other way around, though my problem is not arthritis. My trigger finger is not as strong as it once was, due to an injury. While I could fire a revolver DA in an emergency, I now much prefer one of my Gov't models.

Racking the slide is easier for me than stroking the trigger.

I still fire a few rounds DA through one of my wheelguns, in an attempt to strengthen that finger. Its working, but it is a slow process.

 

[chipperi]

Usually in a gun shop they are just being safe putting the gun on the counter slide back to visually inspect the chamber. I wouldn't consider storing one that way as it will weaken the recoil spring keeping it compressed like that.

 

[Ed Ames]

Most sources say that springs wear from use, not staying still. They say it doesn't much matter whether the spring is under tension or not. So storing pistols with the slide back should be no worse than carrying a 1911 "cocked and locked".

I've stored quite a few guns action open over the years and it's my preference if there is room in the case/safe that way. Slide back and magazine stored separately makes a decent way to lightly secure a pistol.

As for racking the slide if your hand is hurt or you are (temporarily) weakened... make sure the rear sight is designed with a forward-facing wall like this:

(many combat style fixed rear sights are, a few aren't)

instead of a ramp like this:

and learn how to hook the flat front of the rear sight on a table/chair/door frame and push the frame forward to work the slide.

 

[DZL HOG]

Im with chipperi, all the gun stores and gun shows Ive been too all the guns are kept in the cases with slides closed. But if you ask to see/handle one, the guy behind the counter will take out the pistol, rack and lock the slide, and usually look in the barrel to make sure there is no round or anything else in the chamber, then hand it to you.
I store mine closed with loaded mag.
Matt

 

[loop]

Springs are working when they are compressed. The longer and harder they are compressed the longer and harder they work.
Magazine springs are slightly compressed when the mag is empty. Recoil springs are slightly compressed when the gun is assembled.
The only way to completely relieve compression is through disassembly.
Magazines not in use should be stored empty to avoid harm to spring tension.
Guns should be stored with the slide forward to avoid undue stress on the recoil spring.
Storing magazines loaded or slides locked back causes springs to weaken and lose tension over time.
I learned that lesson the hard way years ago. I inadvertently left a couple .45 mags in a box for several years fully loaded. When I used them the last round failed to come up in one and the other failed to lock the slide back when empty (follower did not put enough pressure on the slide stop to make it function).
I would never store a gun with the slide locked back without removing the recoil spring first.
As far as mags go, my carry mags are eight rounders and I load seven to keep from fully compressing the spring.
As far as dealers locking back the slide when they show you a gun - that is the correct way to hand another person a firearm. Both parties can easily see that the gun is unloaded and the chamber is empty.
They teach that in the NRA handgun instructor's course.
Unless you are handing a firearm to another person specifically to fire at a range the gun should always be unloaded. Autos should have the magazine removed and the slide locked. Revolvers should be unloaded with the cylinder open.
And no, I don't store revolvers with the cylinder open either...
My instructor certifications have all lapsed, but included four defensive handgun categories, defensive shotgun and submachine gun.
BTW, shotguns that are stored loaded should have their mag springs replaced at least every two years.

 

[Sport45]

Springs are working when they are compressed. The longer and harder they are compressed the longer and harder they work.

I'll have to respectfully disagree with that statement. If it were true all the coil spring cars and trucks from the 60's and earlier would be setting on their bump stops now and that is just not the case.

Leaving the slide forward lessens the load on the recoil spring but does not unload it. The only way to do that is to take it out of the gun. As long as the spring is in it's region of elastic deformation it should not be hurt by stationary storage in any state of compression. I can see how a coil spring would handle this easier than a magazine spring though. The coil spring works purely in torsion, while the magazine spring is torsional at the front and back of the magazine but is pretty much just a bending wire on the long straight parts.

 

[loop]

The coil springs in trucks are not fully compressed for extended periods of time.
The reason all '60s trucks aren't sitting on their bumpers is the springs have rarely, if ever, been fully compressed and worn out ones have been replaced.
And they do wear out. That's why parts shops and car dealers sell replacements. That is also why they make inserts to go between the coils and jack the springs up a little bit.

Gun springs are different, especially variable compression springs (another subject), but subject to the same laws of physics. They get old and tired.

From the Wolff Gun Spring Web site:
Springs that are subject to higher stress applications such as magazine springs, striker springs and recoil springs will require more frequent replacement than other less stressed springs. ... Some recoil springs in compact pistols, especially where dual springs are replaced by a single spring may require changing after 750 - 1500 rounds.

What I am saying is why needlessly add to the stress of a recoil spring by storing it with the slide locked back? Obviously they wear out...

 

[El Tejon]

You've been in gun shops that keep the slides of their pistols locked back?

Hmmm, O.K., their guns so that's fine but I've never seen that in four decades of haunting gun shops. First time for everything.

I would not be so inclined to keep a pistol is such a condition as dust and filth can collect in the weapon. I would want to keep it ready to go. Just me.

I believe anyone who wishes to use a weapon needs to be able to operate the weapon. To paraphrase Clint Smith, people do not get in trouble because of not being able to shoot, rather because they cannot operate their gear. Just my $.02.

 

[American_Pit_Bull]

Posted by loop:
Springs are working when they are compressed. The longer and harder they are compressed the longer and harder they work.

That is incorrect. And not by a matter of opinion, it is by a matter of physics.

I am not sure how many physics or mechanical engineering classes that you have taken, but I have been through quite a few... No offense, but your assessment is incorrect.

Springs that are forced beyond their elastic limit will wear very quickly, but a properly designed recoil spring will not deform to that point in the normal cycling of the action. The spring doesn't fatigue any faster when it is in the "locked back" position.
And as far as the quote from Wolff... The springs that are cycled the most are fatigued the fastest. Notice that they use a number of "rounds" or cycles of the spring and not a time duration.
There are many examples of people finding 1911 mags that have been fully loaded for decades, that function flawlessly when fired. Some reports of mags that were kept loaded for 40 years that fed perfectly.

Here is an often referenced article about mag spring fatigue: Magazine spring madness...

 

[walking arsenal]

If you do a search on the spring wear topic you'll find we have a lot of members that have worked for companies, are physics gurus etc and almost all will tell you that springs only wear when cycled.

Again, ONLY wear when cycled.

 

[loop]

Sport45, APB, WA, et al,
I read the article referenced, but remain unconvinced. If I were to have researched it I would have interviewed only people who do not have a vested interest in the answers and would have avoided gun makers like they had the plague.
I also would have investigated the degree of compression in recoil springs at slide lock and whether or not that reaches the "elastic limit" - perhaps had it tested by an independent lab. I would suspect it does because of the relatively short life span that can be expected of some recoil springs.
Then I have to believe that every gun maker in the world is so conscientious as to test their springs rigorously enough tested to make sure they fit within the required parameters.
However, I admit your comments and the other things I've read have made me believe I need to do more research on the subject.
Maybe I'll write the next article on the "myth of spring set."
That said, I owned my own metal shop for 15 years and saw tons of spring failure.
And, just yesterday, replaced a failed extractor spring. Must I believe it was loaded past its "elastic" limit? The spring lost its elasticity on the first mag through the gun. It was so un-elastic it broke in two.
I will, also, register my skepticism regarding the particular article I read.
I investigated the author of that article. It is the only serious article I could find that he wrote. However, someone by the same name is very well known for writing comic books...
I do not trust journalists, no matter how conservative or gun oriented they may be. The guiding principle of journalism is to find someone who knows more about the subject than you do and figure out how to explain it to a broad audience - half of which is below average intelligence (actually below mean intelligence, but you can't explain what mean means to those who are below mean intelligence).
Perhaps my skepticism regarding what's in print is due to having a very close relationship with numerous journalists for 35 years and meeting very few I trust.
Or maybe, because two hours ago I signed off on the latest issue of a monthly magazine where my name appears in the attribution box, right next to the word editor, and am now in the pins-and-needles mode waiting to see what some reporter got wrong that I'll have to answer for and write a correction about (the reporter answers to me and, in truth, I make them write their own corrections - best way I've found to get them to quit making mistakes).
Oh well, don't go to prepress until Monday and won't be on the street until Wednesday. At least I get five days of peace...
Anyway, if you want to store your autos with the slide locked back it is quite alright with me. I don't have to rely on them.

 

[WVMountainBoy]

I understand the reasons for keeping the slide in the open position, the courtesy of the visual inspection being the greatest of the bunch. To me though the chance of dust and other nasties contaminating the inner workings is too high. For weapons that don't get as much time out and about, I usually store them in a gun rug, slide closed, with an unloaded magazine in them. I've also lately taken the habit of keeping those little plastic safty slugs that the weapons came with and reusing them as empty chamber indicaters. While I know this does keep the slide slightly open, I think its worth it.

 

[Autolycus]

I think the reason you see them with the slide locked back on television news is that it is known the gun is "safe" with it back.

 

[Sport45]

I don't store any guns with the actions open because I don’t want them filling up with lint and dust. If I'm handing a gun to someone else the action will be open. When I’m at the range the action will be open unless I’m shooting it. I don't know of anyone or any shop that stores pistols with the slides locked back. If I saw this I would be perplexed as well.

Recoil springs do seem to wear out, but I'm not sure I know why. I wouldn't think the gun maker would allow them to stack or coil bind in operation, but I don't know that for sure. I do know that other coil springs can last much, much longer even though they are in a more severe service. Can you imagine having to change your car's valve springs every 1000 cycles? You'd have to change them every 3000 feet or so. These coil springs cycle around 900 times a minute at 60 mph, run hotter than most gun springs and flex to within about .040" of coil stack once for every two engine revolutions. (The relaxed length does shorten over time, but I've always found them to all be the same length even when the engine hasn't been run in decades. A stationary engine will have a few springs fully compressed, a few as relaxed as the keepers allow, and the rest somewhere in between.)

It's hard for me to imagine a recoil spring seeing worse duty than an engine valve spring unless it has to do with lubrication and cleanliness.

I don't publish any magazines or anything, but I do get my hands dirty. I earned my engineering degree a quarter-century ago and what I've said here doesn't contradict anything I've learned, either in school or through practical experience. I have stayed in a Holiday Inn Express, but it wasn’t last night, so I may be all wet.

Y'all have a nice day, enjoy the holiday's and go out and have fun!

 

[gym]

I keep 4 autos loaded with the mags full. never had a problem with any of them in 30 years. I think the popular thinking changed over the years. They sit in the safe that way, so if I want a spcific gun for that day, I can just take it and go. And as a couple folks mentioned, the train of thought seems to have changed on that point. Larry recommends the springs be replaced in the 380 every 3 or 3 years, but the 32, he recomends nothing, the spring should last forever. That would make me feel that the more powerfol round may cause the spring to de compress over time, from use. But his guns use a retarted blowback design, and may differ from say a glock or 1911. He also mentions that just because a round may stick when racking it thru manually, means nothing. Some good info on his site, Over a long period of time it is however smart to run the mags thru a few times to make sure that everything is functioning properlly.

 

[Ed Ames]

Hmm... I'm far from an expert but I may have a bit more to contribute...

Spring breakage is typically caused by a stress riser of one form or another. One form would be uneven temper which causes one section of the spring to deform at a different rate than the rest. This causes a concentration of fatigue and eventual failure. Another form would be a physical defect (a nick, gouge, thin spot, etc) which causes one section of the spring to deform at a different rate than the rest. This causes a concentration of fatigue and eventual failure. Spring breakage is not relevant to the concept of spring set/sag/creep/rate loss.

As for recoil springs....

In a perfect world you would design a pistol so that the slide would just cycle with weak target loads and would travel farther and farther back the hotter the load. You'd design it so that even +P+ loads wouldn't push the slide back far enough to compress the spring past its plastic limit. Unfortunately, that would leave you with a rather bulky pistol. You can use recoil buffers to stop the travel but that has problems too for a very compact gun. The recoil buffer itself can take a pounding and anyway it adds an 1/8th of an inch to the length of the gun.

So, if you are designing a minimum-size CCW, it makes some sense to consider the spring a consumable when used with hot ammo. You leave out the recoil buffers and use a shorter spring to reduce the overall size of the gun. Use that same basic gun with a lower power or shorter cartridge and the spring will not hit its plastic limit... in fact you may be able to add a recoil buffer at which point the spring may last forever.

Car suspension springs sag because the overtravel stops (the rubber bumpers that are supposed to stop the suspension from swinging past a certain point) are either misdesigned or worn. Those stops are the equivalent of the recoil buffers and if they do their job the springs will last forever. Some cars never need new springs and will drive 50+ years on the originals. Others need new springs every 5 years. It comes back to those travel stops (which some cars lack altogether) and the design.

Engine valve springs don't sag because when you design an engine you size the springs to stay within their elastic range. If you fail the springs will self destruct very quickly.

There are other factors... springs are mostly made of tempered steel and if something heats the spring hot enough it can lose its elasticity. As anyone who has broken a wire by bending it back and forth can attest, metal heats up when worked, and it is possible that the heat generated by rapidly and repeatedly forcing a spring into compression may eventually impact the temper. A zippo can destroy the temper of your standard recoil spring in a few seconds.

None of which has much bearing on storing a gun with the slide open. The slide stop on the pistols I've handled is nowhere near max extension... you may have another half inch of slide travel/spring compression.

The argument about stuff getting inside if the action is open may be a good one. Doesn't really apply if the guns are in gun rugs/bore stores/seal-a-meal bags. The argument that the springs will wear out doesn't seem to be quite so good.

 

[American_Pit_Bull]

Posted by Loop:
I read the article referenced, but remain unconvinced.

The problem is that there aren't many physicists or engineers that write articles for gun rags.... Here is a response that was written years ago by Julius Chang, a noted MIT alum that used to post on the news groups...
(The original question is broken into segments in the quote boxes)

Is there any problem with feed spring fatigue in fully loaded
magazines?

If the spring designer, and the metallurgist, are competent, there
should be no fatigue in a spring that isn't stressed beyond it's
elastic modulus. Bad designs, or bad spring metallurgy, can allow

"Stressed beyond it's [sic] elastic modulus" is technically
incorrect.

Elastic modulus E is the slope of the stress-strain curve.
It provides an indication of the stiffness of the material.
I assume that you mean to say "stressed beyond its static
yield strength."

However, fatigue can definitely occur due to cyclic loading
below the static yield strength of the material. Even absent
surface stress risers (e.g., notches), fatigue crack nucleation
can occur at grain boundaries, second-phase particles, twin
boundaries, and other microstructural features which exist
normally.

spring fatigue. As a data point, I inherited a 1911 that had been
loaded since WWI. The springs were fine, so was the ammo BTW. OTOH
I have some off brand mags that suffered noticable spring fatigue
after only being loaded a few weeks. You pays your money, you takes

Since fatigue is a failure mode due to CYCLIC loading,
your observation does not indicate fatigue failure. A
loaded magazine is a static situation, not a cyclically
loaded one.

It sounds like the spring was improperly designed and
it suffered permanent deformation when the mag was loaded
to the max and the spring got compressed beyond its limit.

Fatigue is not a bending type failure. It consists of
crack nucleation/initiation, progressive cyclic crack growth,
and catastrophic failure. Fractographic examination of
of the material commonly shows "river markings", i.e.
ridges or striations which delineate the cyclic crack
propagation.

your chances. Frankly, I wouldn't use a magazine in a carry gun that
I didn't have every confidence that it could stay loaded indefinitely
with no harm.

Note, springs that must flex rapidly, like your recoil spring, can
fatigue with use. The reason is that the rapid and repeated flexing
can raise the spring temperature enough in localized stress risers

I've never heard of this as a fatigue mechanism. Do you
have a reference for this?

My understanding is that fatigue failure is due to localized
plastic deformation and dislocation (slip band) propagation
and is not due to localized heating.

to destroy the temper of the spring in that area. The load will then
exceed the (reduced) elastic modulus at that point in the spring and

As mentioned above, the use of the term "elastic modulus"
here is incorrect. A load doesn't exceed the elastic modulus
since E is the slope of the stress-strain curve and measures
stiffness. What you probably mean to say is that "the load
will then exceed the (reduced) yield strength...."

allow it to collapse or even break. But a static load within the
spring's design limits, like that in a stored loaded magazine, should
never have this problem.

By definition, a static load (e.g., a once-loaded mag
stored indefinitely) can never produce fatigue
failure. You need a cyclic load (e.g., a repeatedly
loaded and unloaded mag).

-Julius

 

[Rustynuts]

A high static load CAN cause creep though, or stress corrosion cracking. There are more failure modes than just ultimate strength or fatigue failure.

 

[bruss01]

I mean, say you have a semi auto the wife shoots fine, but cant work the slide for some reason? Why not keep that slide locked back for her and have 6 or 7 loaded magazines with it?

With all due respect, if the wife cannot operate the slide, the answer is not to leave the slide retracted. The answer is to get her a gun with a slide she CAN operate properly, or a revolver. There are many reasons why a slide might need to be cycled manually - anyone who cannot fully operate a firearm has no business depending on that firearm for personal protection any more than a person should plan on evacuating a life-threatening area in a stick-shift vehicle if they do not know how to drive a stick. She will be better served with a .22 that she can quickly and easily load, cycle and fire than with a .40 where she has to depend on it never getting a jam otherwise the gun becomes a paperweight she has to THROW at the intruder.

 

[loop]

Must confess, at this point I really don't know.
Lot of good arguments here.
I do know I don't trust all spring makers to make springs to within acceptable tolerances. I have a CZ27 that was stored empty for about 50 years after WWII. The recoil spring is weak, the hammer spring moves the hammer forward so slowly you can just watch it creep slowly forwardvand the mag spring is so soft you feel no pressure whatsoever until it has three or four rounds in it.
That's after 50 years of no stress whatsoever. (Wasn't due to sloppy late war production, it was made in 1940.)
Metallurgy is a very peculiar science. It is incredibly easy to change temper or crystallize steel. High end manganese moly tubing is silver soldered because it undergoes structural change on the molecular level at 400f - roughly the temperature of the head of a match.
The spring I replaced a couple days ago was crystallized and it was brand new. Hence, my skepticism regarding manufacturers. I was told it was a "known issue" and sent a replacement spring upon request over the phone.
That means a reputable maker knew it was sending out springs that would not hold up, but did nothing to warn previous buyers or even shops that it was sending out defective guns.
The spring issue becomes very muddled when taken on a broad basis.
I will, personally, look into it in the near future. Who knows? Maybe I will write that next article about "Spring set." Sounds like a good topic to me.
Whether I write the story myself or not, I know I will answer the pertinent questions to my own satisfaction.

 

[JohnKSa]

I will, personally, look into it in the near future.

I've explored this topic and here's what I've come up with--these are assertions that can be (and have been) verified with easily constructed experiments.

• An overcompressed spring will weaken.
• The longer a spring is left overcompressed, the more it will weaken.
• A good quality spring that is not overcompressed can be left compressed indefinitely without significant weakening.

 

[loop]

JohnKSa,

Thank you for boiling it down to, um, shall we say "nut and bolts."

Harkening back to philosophy 101... (This is a favorite of mine, dates back to Plato.)

Statement:
An overcompressed spring will weaken. The longer a spring is left overcompressed, the more it will weaken. A spring that is not overcompressed can be left indefinitely without (significant) weakening.

The argument:
All gun makers make only springs that cannot be overcompressed in the firearms they manufacture, therefore they can never be weakened by indefinite periods of compression.

Extrapolation:
Since all gun makers never make springs that can be overcompressed (correct grammar: overly compressed) in normal use, storing such guns with the slide locked back can never cause damage to the recoil springs.

Is it just me or does anyone else see a hole in this argument?