How full should a mag be for a home defense handgun?

[Steve C]

No reason to worry about magazines failing because they're kept loaded. Double stack magazine springs will reliably feed ammo if kept loaded fully for many years. In my experience they don't suddenly fail to reliably feed ammo.

The springs in my original non-drop free Glock 19 magazines became week enough that the slide stop began to fail to hold open the slide following the last round after 12 years of use but never failed to reliably feed ammo. Rebuilding the mags fixed the problem and they have continued to work perfectly for the last 11 years. I purchased several drop free mags since but the originals are still kept fully loaded as spares and for range practice. Never had any issues with my Beretta 92 mags that I've had just as long or with any single stack 1911 mags that I've used for even a longer period.

I keep most all my magazines fully loaded. Had a 1911 mag that was kept fully loaded for over 20 years that had been carried in my old pick up and then dropped into a box of stuff I'd taken out of the vehicle after selling it. Found it and took it to the range and the magazine fed and the round all fired.

 

[Mykey]

Full + 1 ...... Always!

 

[Lawdawg45]

Half full? 3/4 full? Completely full?

Will storing the full amount of rounds decrease spring tension longevity and weaken the spring over time? How often should the rounds be removed from the magazine to give the spring ample time to rest/reset, or should the magazine be disassembled and the spring be stretched back to original length? How often should this be done?

E.g., for a 15 round max 9mm pistol, how many rounds should be stored in the mag for home defense as to not weaken the spring?

-How many for a 10 round .45 1911 style pistol?

I've always wondered what everyone recommends.

Thanks.

Easy answer, Illinois doesn't allow you to load your magazines!

LD

 

[briansmithwins]

As far as the shotgun thing goes, I have had shotgun magazine springs take a set and cause FTFe stoppages.

My cure was to rotate the mag springs monthly. These were 8 round may tubes and they did take a toll on the springs.

BSW

 

[ATLDave]

Full magazine for HD, though I do not keep one in the chamber. In fact, I keep the magazine out of the well itself. If I wake up in the middle of the night to a noise downstairs, I want to make sure I'm awake enough to responsibly handle a firearm. Making myself insert the magazine and operate the slide is part of that. (If I lived on the ground floor in a rough neighborhood and did not have 4 dogs, I might be more worried about reaction time.)

At any rate, I've kept the mag full on my primary HD pistol for about 8 years, and shoot it empty several times a year. Have yet to have a problem.

 

[dusty14u]

Do you keep your fire extinguishers full or half full? I opt for full plus one in my semi's.

 

[HKGuns]

Springs lose tension through the cycle of compression and decompression. Leaving it fully loaded (or unloaded) won't matter either way.

Springs wear from use, not just being compressed.

I keep mine full too.

However, I wish people would please stop spreading this false information about springs not wearing out under torsion.

Magazine springs are compression springs and they DO wear out from being compressed, the range of the loading affects how fast they wear out. So, using them and exposing them to a varied load will wear them out faster than just leaving them full, however, both certainly do wear out a spring.

Stress: The dimensions, along with the load and deflection requirements, determine the stresses in the spring. When a compression spring is loaded, the coiled wire is stressed in torsion. The stress is greatest at the surface of the wire; as the spring is deflected, the load varies, causing a range of operating stress. Stress and stress range govern the life of the spring. The higher the stress range, the lower the maximum stress must be to obtain comparable life. Relatively high stresses may be used when the stress range is low or if the spring is subjected to static loads only. The stress at solid height must be high enough to permit presetting, yet low enough to avoid permanent damage since springs are often compressed solid during installation.

 

[xXxplosive]

All The Way..................FULL....always.

 

[danez71]

1) Half full? 3/4 full? Completely full?

2) Will storing the full amount of rounds decrease spring tension longevity and weaken the spring over time?

3) How often should the rounds be removed from the magazine to give the spring ample time to rest/reset,

or

4) should the magazine be disassembled and the spring be stretched back to original length?

5) How often should this be done?

6) E.g., for a 15 round max 9mm pistol, how many rounds should be stored in the mag for home defense as to not weaken the spring?

7) How many for a 10 round .45 1911 style pistol?

I've always wondered what everyone recommends.

Thanks.

Lets break this down.....

1) I keep mine full.

2) Yes. I, along with a couple of other have posted a boat load of info supporting this fact. Others that disagree arent reading or maybe not understanding the data. Nothing lasts forever! However, generally speaking, a full size gun/mag will not lose enough springy-ness to not work if kept loaded for years.

3) Springs will never reset by their own.

4) Restretching the springs only works temporarly and will shorten the spring life over all.

5) Never. Well, if your 2 days away from new springs and you know a grizzly coming to eat you tomorrow... you might give it a try.

6) Any tension on the spring reduces the life to some exent. The more tension the more it reduces life. There is not one right answer as there are too many different variables. Re-read#2

7) It would depend on a lot of things. My take is this. It was designed as a 7 round mag I believe. That mag was X" long. IF your 10 round mag is the same length, then keeping 7 to maybe 8 rounds should give you the ability to keep it loaded for probably a couple decades and still function. Any more rounds will shorten its life... how much, only time or scientific tests using data we dont have will tell.


Assuming quality materials, the two biggest things that will affect spings will be the number of cycles and how deep the cycle is in terms of range of motion.

If you take a spring and compress it 5% of its range, you could keep it that way for decades with little impact.

Compress the spring 95%, and in a short amount of time, it will lose much of its elasticity.


One thing to keep in mind is that if spings ONLY wore out from being cycled, as many people like to mislakenly say, we would see about 20-30 times or more as many 'replace slide springs' threads as we do 'replace mag spring' threads.

But we dont. The #'s seem fairly equal.

 

[Art Eatman]

I acquired eleven semi-auto pistols which had been in storage for around forty years. Half a dozen WW II bring-backs among them, from Walther P-38 through Mausers on down to a Lilliput.

All with full magazines. All the pistols functioned as one would have wanted them to.

 

[BeerSleeper]

Shoot regularly, and shoot a lot.

If you have a mag spring issue, you will detect it. Don't forget, failure to lock the slide is often a symptom of a weakening mag spring.

When you have cause to suspect an issue, change the spring.

If at this point, whether the spring wore out from cycling, or from sitting compressed is what you are worried about, you have too much time on your hands. Worry less, and take up a hobby. I recommend a shooting sport.

 

[Sapper771]

Full

 

[Patrice]

Hhmmm....I'm old school and have seen too many years of threads & other verbalized opinions re: whether leaving a magazine loaded will weaken/set the springs. I know what the current conventional wisdom is on the subject, but I'm old enough that I've seen that "wisdom" change over the years.

I load the mag to capacity & chamber a round; I don't carry mag-capacity+1. As far as back-up magazines...I down-load by 1 round if they're going to be left at the ready for an indefinite period of time. No science, engineering, or conventional wisdom guiding my actions...I do what I'm comfortable doing; and I'll accept whatever consequences be, come good or bad.--Patrice

 

[Wanderling]

Yes, heavily compressing the spring will indeed reduce it's useful life. Not just the number of cycles. How soon will it happen depends entirely on the design of the spring and how much compression it takes when fully loaded; thus it is somewhat gun specific. For most guns it's probably not an immediate concern. The uber loaded double stacks may be more at risk, but there's just too many variables - quality of design, material and fabrication, tolerances, etc.

Just to be safe, and to make counting easier, I usually load my 17 rd mags to 15 rds. I feel pretty well stocked with anything more than 10.

 

[beatledog7]

Full, and one chambered.

 

[Certaindeaf]

It's not really loaded if it's half or 15/16th's etc loaded.. it's half loaded or 15/16th's loaded. Skotem full up.

 

[JO JO]

FULL, mags are tougher than one might in unit practice mags are loaded,shot,droped in
dirt/mud over and over, ready locker there stored full never seen an issue yet, if its a
good mag not a cheap knock off it should last a long time and be reliable.

 

[Certaindeaf]

FULL, mags are tougher than one might in unit practice mags are loaded,shot,droped in
dirt/mud over and over, ready locker there stored full never seen an issue yet, if its a
good mag not a cheap knock off it should last a long time and be reliable.

What?

 

[cfullgraf]

Hhmmm....I'm old school and have seen too many years of threads & other verbalized opinions re: whether leaving a magazine loaded will weaken/set the springs. I know what the current conventional wisdom is on the subject, but I'm old enough that I've seen that "wisdom" change over the years.

Metallurgy of spring steels today is vastly improved over the technology 100 plus years ago. In the early days of semi-auto pistols, the steel used in magazines springs might well have taken a set and relaxed over time.

Now a days, it is not an issue as long as the spring is properly designed and not compressed to near or beyond the plastic deformation limit of the spring. I doubt any quality magazine used properly would have a problem with springs getting soft.

 

[cfullgraf]

Oh, yes, i keep mine full.

 

[W.E.G.]

17-round for 16 in the mag +1 in the chamber.

Leaves me a place to put the round from the chamber if I have to remove the mag.

 

[MachIVshooter]

However, I wish people would please stop spreading this false information about springs not wearing out under torsion.

See:

I acquired eleven semi-auto pistols which had been in storage for around forty years. Half a dozen WW II bring-backs among them, from Walther P-38 through Mausers on down to a Lilliput.

All with full magazines. All the pistols functioned as one would have wanted them to.

Me experience has been the same. In fact, even the little Llama IIIa that was my grandfathers, which aren't noted for especially high quality, functions fine on a magazine that I know for a fact was left fully loaded for 22 years before I came into possession of the gun.

You only need to worry about it if you're compressing the spring further than it was designed to be, like some folks who trim the protrusion on the bottom of the follower to get an extra round or two in.

Think of it in terms of automobiles; How many museum and showroom cars that haven't been driven (much) are sagging on their original 40, 50, even 70 or 80 year old springs?

 

[Lawdawg45]

Hhmmm....I'm old school and have seen too many years of threads & other verbalized opinions re: whether leaving a magazine loaded will weaken/set the springs. I know what the current conventional wisdom is on the subject, but I'm old enough that I've seen that "wisdom" change over the years.

I load the mag to capacity & chamber a round; I don't carry mag-capacity+1. As far as back-up magazines...I down-load by 1 round if they're going to be left at the ready for an indefinite period of time. No science, engineering, or conventional wisdom guiding my actions...I do what I'm comfortable doing; and I'll accept whatever consequences be, come good or bad.--Patrice

This also was strongly advised by our department Armorer.

LD

 

[KeithG]

You only need to worry about it if you're compressing the spring further than it was designed to be, like some folks who trim the protrusion on the bottom of the follower to get an extra round or two in.

So doing would be illegal in my state, but if I were to trim the follower and fill the space formerly occupied with plastic with a cartridge or two, would the spring be compressed any farther? My logic says, "No." What am I missing?



Sent from my SGH-T989 using Tapatalk

 

[Rail Driver]

So doing would be illegal in my state, but if I were to trim the follower and fill the space formerly occupied with plastic with a cartridge or two, would the spring be compressed any farther? My logic says, "No." What am I missing?



Sent from my SGH-T989 using Tapatalk

The spring is under the follower. The rounds go above the follower. The protrusions on the follower prevent the spring from being overcompressed. Cutting them and putting in an extra round or two compresses (or overcompresses) the spring because the protrusions aren't there to stop the follower from going down further (thus allowing the insertion of the extra rounds) and allows the spring to be overcompressed or "stacked".