Talyn
SAINT
A question that routinely comes up when a new user gets an auto pistol – whether a police trainee or armed citizen – is “how long can the magazine stay loaded without compromising reliability?” – or words to that effect.
Magazine Fatigue?
- Thread starter Talyn
- Start date
The Night Rider
Professional
This question is commonly asked. I've read several of these discussions. The following is the best information I've found.
This was written by an engineer who participated at THR username Charlie Sherril.
Springs have a compression limit. If you compress a spring beyond that limit it will deform immediately and it will never work right again. If you compress a spring close to that limit it becomes susceptible to "creep strain" which will eventually cause it to fail.
The majority of gun manufacturers design their magazines so that even when fully loaded the load never approaches that compression limit. The problem is more with the off brand magazines like Pro Mags.
This is me
Magazines are expendable. Buy spares
Even though my research indicates that it's really not necessary, I keep enough magazines on hand for a given gun that I can put them through a long rotation cycle. 1 year loaded /5 years in the box. At that rate they should out last Methusala.
The question of "fatigue limits" and "creep strain" (which apparently is only a factor at 4X the melting point (Degrees Kelvin) of a given metal) is discussed in detail here
Does static tension wear out a spring? | Physics Forums
This is another article about how springs are engineered with the concept of "set" already factored in. I assume that most magazine manufacturers order their springs just a little long to "allow for set". For instance the Shield magazines that are initially so hard to load. Once the owner loads the magazine the first time the springs take that "initial set" and after that even compressed solid they don't approach the compression limit
Compression Spring - Stress and Spring Set
Compression Spring Set
When a custom spring is supplied longer than specified to compensate for length loss when fully compressed in assembly by customer, this is referred to as “Allow for Set”. This is usually recommended for large quantity orders to reduce cost. When a compression spring is compressed and released, it is supposed to return to its original height and, on further compressions, the load at any given point should remain constant at least within the loadlimits specified. When a spring is made and then compressed the first time, if the stress in the wire is high enough at the point the spring is compressed to, the spring will not return to its original height (i.e., it will get shorter). This is referred to as "taking a set", or "setting". Once the spring is compressed the first time and takes this set, the spring will generally not take any significant additional set on subsequent compressions.
One way to deal with this problem is to make the spring initially a little bit too long and then compress the spring all the way to solid so that after the spring takes the initial set, it is now at the correct height to meet the loadrequirement. This is referred to as "presetting", "removing the set" or sometimes "scragging". Presetting is a labor intensive and relatively costly operation due to the amount of handling of the springs involved. In most cases, the customer will also handle each spring as the springs are assembled into the product. As part of this handling, the customer could press each spring and "remove the set" so that the spring will be stable and perform satisfactorily. Another alternative would be to assemble the spring as is and allow the first operation of the mechanism into which the springhas been assembled to "remove the set". In either case, in order for the spring to be correct after removing the set, the spring would have to be received by the customer in a condition longer than the final height.
This was written by an engineer who participated at THR username Charlie Sherril.
Springs have a compression limit. If you compress a spring beyond that limit it will deform immediately and it will never work right again. If you compress a spring close to that limit it becomes susceptible to "creep strain" which will eventually cause it to fail.
The majority of gun manufacturers design their magazines so that even when fully loaded the load never approaches that compression limit. The problem is more with the off brand magazines like Pro Mags.
This is me
Magazines are expendable. Buy spares
Even though my research indicates that it's really not necessary, I keep enough magazines on hand for a given gun that I can put them through a long rotation cycle. 1 year loaded /5 years in the box. At that rate they should out last Methusala.
The question of "fatigue limits" and "creep strain" (which apparently is only a factor at 4X the melting point (Degrees Kelvin) of a given metal) is discussed in detail here
Does static tension wear out a spring? | Physics Forums
This is another article about how springs are engineered with the concept of "set" already factored in. I assume that most magazine manufacturers order their springs just a little long to "allow for set". For instance the Shield magazines that are initially so hard to load. Once the owner loads the magazine the first time the springs take that "initial set" and after that even compressed solid they don't approach the compression limit
Compression Spring - Stress and Spring Set
Compression Spring Set
When a custom spring is supplied longer than specified to compensate for length loss when fully compressed in assembly by customer, this is referred to as “Allow for Set”. This is usually recommended for large quantity orders to reduce cost. When a compression spring is compressed and released, it is supposed to return to its original height and, on further compressions, the load at any given point should remain constant at least within the loadlimits specified. When a spring is made and then compressed the first time, if the stress in the wire is high enough at the point the spring is compressed to, the spring will not return to its original height (i.e., it will get shorter). This is referred to as "taking a set", or "setting". Once the spring is compressed the first time and takes this set, the spring will generally not take any significant additional set on subsequent compressions.
One way to deal with this problem is to make the spring initially a little bit too long and then compress the spring all the way to solid so that after the spring takes the initial set, it is now at the correct height to meet the loadrequirement. This is referred to as "presetting", "removing the set" or sometimes "scragging". Presetting is a labor intensive and relatively costly operation due to the amount of handling of the springs involved. In most cases, the customer will also handle each spring as the springs are assembled into the product. As part of this handling, the customer could press each spring and "remove the set" so that the spring will be stable and perform satisfactorily. Another alternative would be to assemble the spring as is and allow the first operation of the mechanism into which the springhas been assembled to "remove the set". In either case, in order for the spring to be correct after removing the set, the spring would have to be received by the customer in a condition longer than the final height.
WellArmed
Master Class
Mag springs wear out from being constantly compressed and decompressed. The more they're loaded, unloaded, and ammo is rotated out, the weaker they'll become as opposed to leaving them fully loaded and compressed for long periods of time.
I have AK and AR mags that have been loaded for several years now. I don't unload my pistol mags unless they're dirty from EDC'ing them.
I have AK and AR mags that have been loaded for several years now. I don't unload my pistol mags unless they're dirty from EDC'ing them.
TEXASforLIFE
SAINT
whether it be 30 round or more in ar style mags i haven't had any issues in usage for very prolonged loaded storage. pistols operated the same as the ar mags, except in promags as springs got weak. p90/ps90 50 rounds will fail as they have on me after 1 year of loaded to max (50 rounds) storage. fn and aftermarket for the p/ps90 have done this in my experience. 3 and 5 round single stack rifle mags are gtg.
Indefinitely with no issues!
Where springs get weakened is by use.
Whe I transferred to the Aur Guard we had pallets of loaded magazines in a mobility box that had been there for over 29 years. Since it was older 55 grain and we were running 62 grain they decided to use it and replace with new.
We ran all the mags empty from full with zero issues like 50,000 rounds worth.
I have also heard the same conversation from national LE trainers I trust that reported the same with pistol mags and such.
Where springs get weakened is by use.
Whe I transferred to the Aur Guard we had pallets of loaded magazines in a mobility box that had been there for over 29 years. Since it was older 55 grain and we were running 62 grain they decided to use it and replace with new.
We ran all the mags empty from full with zero issues like 50,000 rounds worth.
I have also heard the same conversation from national LE trainers I trust that reported the same with pistol mags and such.
belladonna
Hellcat
Good to know.
KillerFord1977
SAINT
Trust what the metallurgic engineers say
The Night Rider
Professional
Sitting on the curb at WaWa?
youngolddude
Professional
At first I thought this was about gun magazines, you know pics and stories. I've looked at them for years and funny how the same guns show up in different magazines. It's like the Democrat talking points that are distributed daily.
Annihilator
Emissary
In my many years of using auto pistols I never had any mag fail due to a weak mag springs, when we moved 2 years ago I was rumiging through some old gun stuff and found a old .45 Wilson magazine that was still loaded, probably been in my box of stuff for over 20 years. I just recently loaded it up and it worked flawlessly…..this is like the 9mm vs .45 debate, now don’t get me wrong, it’s a very good ideal to always check your mags especially if there for your EDC gun, but I think this whole shabang over weak springs is just a way to get some anxious so they go and buy new mags, just me.
Porschedog
Alpha
I know a guy who has a bunch of AR mags that have been loaded since Y2K was concern. "He" says they are still good to go.
Can’t speak to long gun magazines, but I’m pretty sure the cost of a pistol magazine spring isn’t going to lead me to become destitute. I think the last springs I bought (some Wolf Springs #11 for G43 magazines) were around $20 for 10 springs; yes, I have that many magazines for one gun. I hate taking time to reload at the range if I can help it!
Belt Fed
Ronin
KillerFord1977
SAINT
That gun needs some shooting love.. burn that mag
KillerFord1977
SAINT
Tell us how they shoot when you take them to the range
