Leave Mags full or empty?


September 22, 2006, 02:12 PM
I have a Ruger KP345PR and was wondering if it was okay to leave the mags full for defense purposes because one of the guys I work with said that it's good to rotate mags so that the springs don't get worn out from being depressed all the time.

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September 22, 2006, 02:37 PM
The only magazines I've ever had go slack from loaded storage were cheapola aftermarket knockoffs. Good mags use wire in the springs of sufficient diameter that its critical point (that is, the point to which you must bend it to make it stay bent) is beyond what the spring as installed in the magazine is physically capable of.

Usually, anyway.

New mag springs are cheap, and taking out the worn ones and giving them a stretch is dead simple to do.

September 22, 2006, 02:44 PM
+1` to what Zero said. Go ahead and keep your Ruger mags loaded. Quality magazines can be kept loaded for decades.

September 22, 2006, 03:14 PM
It's actually cycling the spring (loading and unloading) which wears it out. Leaving a magazine loaded for a year is easier on it than unloading and reloading it every month.

Black Majik
September 22, 2006, 03:16 PM
Yup, Ryan M is correct.

Leaving the mag springs compressed at a static state does less harm than actually cycling the springs (such as loading and unloading, or shooting the gun like you're suppose to).

Go ahead and load em' up. It won't wear our your magazine spring.

September 22, 2006, 03:18 PM
The only time I'm unload them is when I fire them and then I quickly reload them again. I have never had any problems with them. Anyway, there pretty cheap and easy to replace if the springs every do wear out. I haven't had one fail yet and I fire alot of rounds all the time.


September 22, 2006, 04:40 PM
Not to mention that unloaded mags cause problems in a gunfight.

September 22, 2006, 04:51 PM
I have 3 mags loaded at any given time for my house gun. I will also rotate out mags from time to time & also rotate out guns too.

September 22, 2006, 05:22 PM
Cops carry mags fully loaded all the time. For long periods and in all kinds of weather changes. Load 'em up. That's the way they are designed.

September 22, 2006, 05:34 PM
Keeping mags loaded is figured into the spring design.

Generally, keeping a spring compressed to its limit of design won't wear it out.
Its the cycling (compression and decompression) that wears it out.

So, loading and unloading the mags will wear the springs out faster than just leaving them loaded.

September 22, 2006, 07:57 PM
Mag springs will not weaken over time but some cheapo aftermarket mags will. The only thing you want to do is unload and rotate your rounds from time to time to prevent them from misforming and causing jams.

September 22, 2006, 09:04 PM
All my mags are kept loaded minus one round. Even my 1911 mags are Chip McCormick 8-rounders so I still have 7+1 in the pistol.

I do the -1 thing not because I worry about spring fatigue. I want them to fully and easily lock in when doing a reload with the slide closed. So far, after almost 30 years of shooting pistols I have not had to replace one magazine spring.

Travis McGee
September 22, 2006, 09:46 PM
Not to mention that unloaded mags cause problems in a gunfight.


September 23, 2006, 12:04 AM
I do the -1 thing not because I worry about spring fatigue. I want them to fully and easily lock in when doing a reload with the slide closed. So far, after almost 30 years of shooting pistols I have not had to replace one magazine spring.

+1 on this excellent advice. I do the same thing. It's embarrassing to drop a full mag out of your gun, right when you need it.

September 23, 2006, 12:11 AM
One thing that can help with the problem of seating mags is to also always push-pull when inserting a magazine. This will also eliminate the need to "tap" while clearing a jam. Downloading by one and using push-pull is especially helpful at preventing jams when using an AR type rifle.

September 23, 2006, 12:21 AM
Full usually with Rangers!

Steve C
September 23, 2006, 12:41 AM
Magazine springs do wear out on high cap magazines. I wore the springs out on 3 Glock 19 magazines in 10 years of keeping them full loaded and shooting them out of course. When a springs began to fail the effect wasn't the magazine failing to feed ammo but the springs became unable to reliably lock the slide stop on the last round. New magazine springs from Wolf got them back in 100% working order. The springs on a single stack mag like the 1911 are all but impossible to wear out.

September 23, 2006, 12:55 AM
I keep a few mag's for each pistol loaded all the time. The rest I use quite often. The loaded one's get used from time to time, just to make sure they still work. I found 2 1911 8 round 45 mag's & some 22 pistol mags that have been fully loaded for over 10 year's. I had put them in a box while moving back then & had forgotten about them. I figgured that I would have to replace the spring's or trash them or something. SUPRISE! They alll work like new! I don't think leaving a mag loaded for a long period hurt's them at all.

September 23, 2006, 01:11 AM
I've been doing a little test with my 1911 magazines, 7rd Mecgar and 8rd Chip McCormick (CMC, Colt and Kimber stamped). I currently have over 40 mags, some I have owned for over 5 years now, some as young as 6 months. All have been loaded to capacity 24/7/365 except for the time it takes to get home from the range and reload. Every single magazine still functions 100%.

September 23, 2006, 08:13 AM
From: American Handgunner > May-June, 2003


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

September 23, 2006, 08:13 PM
Yeah, "John S. Layman" pretty much has it right except that he implies that there are no magazine designs that overcompress the springs. I don't think it's common now, but when the wondernines were really hitting their peak, there were some companies that were willing to do anything to max out mag capacity. Some of those magazine designs effectively overcompressed the springs when fully loaded.

Rotating the magazines isn't going to address the real problem. If you overcompress the springs, they've been weakened--although the longer they're overcompressed the worse it is, simply rotating them out to let them "rest" doesn't undo the damage. If you notice that the mag springs in a particular type of pistol mag weaken when left fully loaded, you're better off replacing the springs and underloading by one in that type of mag.

September 23, 2006, 08:35 PM
I do the -1 thing not because I worry about spring fatigue. I want them to fully and easily lock in when doing a reload with the slide closed. So far, after almost 30 years of shooting pistols I have not had to replace one magazine spring.

I do this as well but with my ar-15 mags

I keep two mags loaded at all times for my home defense gun, and my carry gun. i rotate my defense ammo out every so often but i don't worry about the mags going bad, like was said before as long as you have good factory mags you will be good!

September 23, 2006, 08:43 PM
So that's the point of 'rotating ammunition'.

Sticky this topic somewhere - it's a question that always seems to be asked.

September 23, 2006, 08:55 PM
The only time I rotate ammo is so that I don't keep chambering the same round over and over again. My Gold Dots did not handle being chambered over and over again. I have not had the problem with any other ammo but the Gold Dots seemed to compressinto the brass.

September 23, 2006, 09:43 PM
I've heard different sides on the subject of mag springs/loading.

Some gun owners/firearm experts state that the metal used in the wire springs are strong enough to last for long periods.

Other sources(like the US Army, :D ) say to not fully load magazines to help keep the mags working longer.

My feelings are if you keep a fully loaded magazine it should be ok. I would use new magazines when possible and would not store all weapons with loaded magazines. Just the ones used for protection/duty/CC.

If for example you have a 9mmNATO pistol with 15rd magazine, if you load spare mags with 10rds it would be fine.

Check your mags often for wear and do not use cheap gun show magazines for duty/CCW use. ;)


September 23, 2006, 11:37 PM
Beretta, in the 92 manual half-heartedly recommends not topping off a magazine when loading a gun. The rationale given is that when a full mag is inserted into the gun it puts extra pressure on the magazine spring since there has to be downward pressure from the slide onto the top round for things to work right during the feeding process** which results in more spring compression than would be experienced in a fully loaded spare mag. (** Saying it the other way around: If there is no pressure upwards against the bottom of the slide from the top round, the top round will not pop up when the slide moves out of the way during rearward travel and therefore will not be available to feed into the chamber when the slide comes back forward.)

Here's the quote:During normal chamber loading, as described above, the pistol contains one round in the chamber plus 14 rounds in the magazine. This is an advantage because the magazine spring is not fully compressed but under about the same tension as a 15-round loaded spare magazine.

What this says to me is that this magazine is designed so that a fully loaded spare magazine has the spring compressed to maximum (or at least close to maximum) design limits. So close that Beretta feels it's worth stating that it is advantageous to not top off to keep the pressure on the mag spring below a certain level.

However, they then go on to explain in detail how to top off, so clearly they're not worried about something self-destructing in the short term.

I think there are two primary misunderstandings that keep this debate alive.

1. Just because some say that there are certain circumstances that can cause a spring to be weakened from merely being left compressed does NOT mean that EVERYONE should rotate their magazines/ammo or that EVERYONE should underload their mags. It is CLEARLY not an issue with all magazines. Single column mags seem to be virtually immune, and even most double-stacks don't have a problem.

2. Much of what is stated about the nature of springs (in support of not EVER underloading or rotating mags/ammo) is correct but ONLY in the ideal case. That is, springs not overcompressed, excellent spring design, high quality materials and proper manufacturing techniques. CLEARLY, not all those things apply to every magazine ever made.

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