To get ahead of some of the comments. This is massively simplified, and ignores some other intervening variables that effect theoretical yield strength, cyclic failures, creep, material choice of the feed lips etc. You should more view this simply as hyper simplified crash course on long term material fatigue specifically in regards to leaving mags under compression for long periods, and the springs failing.
Practical advice: Do not fully load plastic magazines for long term storage, store 28/29 in 30rd mags. Cracked feed lip on Magpul M2 mags maybe due to weaker plastic. Fully loaded mags may not tactically reload as easily too.
Of course, but it should be noted that this only applies to springs made out of spring metal. I was so confused as a Pvt. when the Berretta M9 was a single shot with a box of 14 loose rounds rattling around in what is supposed to be a magazine, kind of like the bb hopper on a daisy air gun. It soured me on Berretta for some time until a few civilian cops who carried Berrettas swore by their reliability. Turns out that the army had purchased mostly CheckMate brand mags. CheckMate seems to have saved on production costs by replacing the spring with something that looks like a spring but I believe to actually be bailing wire. The army likely bought these magazine shaped objects instead of magazine because Berreta wouldn’t sell copyright to any company that actually makes gun parts and of the cost of Berretta mags. You hear stories of people waking up in an ice bath missing a kidney. It is an undisputed FACT that in every recorded case, the kidneys were being traded for Berretta mags at a 3:1 rate, and most of us only have 2 kidneys at a time so another has to be sourced from a local bar Never drink anything given to you by the owner of a Berretta. Berretta never says why the need so many kidneys, but it is theorized that it keeps the original 15th century master gunsmith going in a dark cellar beneath a castle that is always surrounded by clouds and howling wolves. Once I sold enough blood plasma for shipping and sourced enough kidneys from drunken pac clerks to buy Berretta mags the problem went away and I had presumably the only M9 in the army that had 3 15 round magazines and could each fire 15 consecutive rounds without a jam. Also without pac clerks my entire unit entered a period of time without pay problems. I found just how sinister Berretta is when I bought my own. It came with only one ten round magazine! Much like the shady guy in the alley Berretta reaches into their curiously fashionable trench coat and says “come on kid, the first one is free.” This ensures the owner of Berretta has a steady supply of kidneys to keep him going for yet another century of producing high quality firearms.
I’m studying for my Level 3 exam in magnetic particle testing and this video is pretty much 30% of what I had to study for the Basic exam. You just blended my hobby with my career. Good on you man.
Ya, I am convinced this dude is a genius. He makes it all seem so simple. That's what Einstein said about geniuses, they can explain things to dummies like me. lol
To piggyback on this…I had the privilege of shooting some bill drills with grandpas 45 mags that were loaded for decades in a Wilson 1911. I kept a few loaded for nostalgia but they ran flawlessly.
Funny enough, I had experience with some magazines that I assume were left loaded for 80+ years… because I had no reason not to believe so. Let me elaborate. So my great grandfather was a WWI vet. Brought back his 1911, which was made in 1917 (after looking up the serial number). I found this pistol loaded in my grandfathers basement in its flap holster, with a small coffee can with some extra ammo. All the headstamps were UMC 17’ and this was in 2010 😂😂. Anyways, I was safety checking the pistol, upon removing the mag I noticed the feed lips were split. Looked at the other two spare mags, which had also been left loaded and their feed-lips were also damaged. While checking the tension on the springs I noticed they still were quite strong and had the feed lips not deformed would be totally serviceable magazines. Was pretty impressed. Anyways just an anecdote.
@@tehmediasource “ while checking the tension on the springs I noticed they still were quite strong “ your own words, so I pointed out how springs don’t deteriorate from static load. Apparently reading comprehension isn’t your strong suit
@@Pickledlizardnipples this was like 10 years ago, even still. The entire point of this video was that message. Are you this fun at parties, or are you unaware of what an anecdote is?
An engineer? As a mechanic, we are now mortal enemies. Great video. Gotta love boomers. Never seen any group of people claim to know so much while simultaneously knowing jack about what they “know”.
To add to your creep portion. Creep is also highly influenced by how far along the stress-strain curve you are. Magazine springs are designed for high amounts of compression. This means a fully loaded magazine is actually very low relatively along the stress-strain curve in compression, even when fully loaded. They are specifically designed and engineered this way. The creep at room temperature because of this can be measured in hundreds of years to become even partially inoperable. You would have to compress the springs to the point of smashing the steel flat against itself or somehow push the spring through/past itself to get enough strain to cause any plastic deformation. The spring in normal operation would never be compressed enough to even register any perceptible creep within several lifetimes. The bigger issue/danger for magazine springs is actually in extension. They are designed to greatly withstand compression and by their mechanical design, aren't going to be able to be compressed enough to really cause any damage. This is true of most springs. The danger of extension is that there's no hard mechanical limit preventing the spring from being stretched beyond its strain limit. You can permanently damage your magazine spring for example by removing the bottom plate, having your spring snag or somehow stuck to that plate and forcing the plate off and pulling the spring. The reason why "boomers" have this experience is because of cheap knock-off manufacturers of the 80s and 90s not bringing their springs to the proper temper or not using enough coils in their spring and instead tempering them at higher angles between coils to compensate for less coils. They did this on both fronts to cheap out on production costs, but this resulted in springs that could be compressed (elongated negatively) much further along the stress-strain curve than a compression based spring should be. The result was a spring that when fully compressed as intended would be sitting at around the 60%-70% travel down the elastic region curve which greatly accelerates creep. If they had an engineer, they didn't care because the magazines still functioned and the deficiency only reared its ugly head for long-term storage. In other words, they'd be safe. The results of this were that people would lose magazine functionality after a very short relative time storing a fully loaded mag. You'd then see issues where a mag fully compressed and stored that way for a while would only feed 28 out of 30 of a 30 round STANAG mag. This is why it's so common among the AR circles for many of the older heads (or those trained by said older heads) to store 29 or 28 rounds in the magazines long-term and it'll all be fine. This is because removing 1-3 rounds brings the spring drastically back down the stress-strain curve and gives you the creep you'd expect. You can see this with very old ProMags where they'd have fewer coils on the spring (shorter spring) at a more aggressive set (looks like its stretched out more naturally to make up the difference.) I remember this being a very common issue in the 90s especially as people started sifting through the older mags from the 80s and more companies started jumping into the magazine scene with the advent of much more easily obtainable plastic/resin technology.
The crash in 07 didn't fully hit me until 09. At that time I lost pretty much everything. I ended up putting a bunch of my stuff in storage in my parents attic while I started traveling for work. In that, there were a couple of gi mags and old pmags fully loaded that sat until I finally got off working on the road. I finally got around to shooting those mags last year. They all functioned flawlessly, but the 2 pmags did not lock back.
We're post 2020. Combining your cheaply bought ammunition from 2019 that you were never going to shoot with the pmags you bought "in case they ban them" seems perfectly logical. If things get weird enough for me to actually need all my cool guy stuff, I think I want a big box of spicy pez dispensers ready to go
Nice video bro, I too am a fellow nerd and it's nice to see real engineering about guns. Keep up the good work. Now for my bone to pick on a passing statement you made: 5.56 will def still be around in 50 years. 9mm has made is 120 years and is still the king of handgun calibers. 30-06 is 115 years old. .45 ACP is again over 110 years old. The list goes on an on. Good calibers stick around, which means more guns chambered in those rounds are made, which then feeds back into more of that ammo production. There are now so many .223 / 5.56 weapons in the USA alone that would make stopping production of those calibers a very unwise financial mistake. Sure, calibers may wax or wane in popularity over decades, but considering the AR-15 is America's favorite rifle right now, there is no reason why the 5.56 would not be made in 2070 barring Armageddon between now and then.
If your speaking and looking at the fact most of the gun community and ammo industry now adays plays off of the military world, I’d still say probably not. Look at what the ammo type the us is looking at now, 6.8. There will be so much 5.56 left over if that happens and so many guns in the us that no one will want to not supply that type. Also I don’t think the whole military will change over to the 6.8 any time soon. To much training to the round will be needed. To many weapons to swap out. And again to much surplus ammo in bunkers right now. Not to mention in a SHTF senecio, 9mm, 12g, 5.56 and .308 will be the most available and useable rounds. Maybe once we start seeing reliable shoulder fired laser blasters like from Star Wars willl we see 5.56 go away. But untill then it’s still gona be dropping dudes and paper.
Engineer here. What I’m wondering is how you afford (time and money) to have all this gucci gear, time to shoot+ammo, make YT vids, have a job?, AND get through engineering school. Keep it up.
being single is probably the biggest factor. money is mostly having money saved up from before school, and basically selling everything I review such that operating cost is basically just ammo.
This took me way back to my second year architecture strength of materials class (in 1970 - damn I'm getting old). Because I understood everything you said I felt smarter than I probably am.
I have an enfield mag that I found in about 1993 that was presumably loaded in WW2. The .303 round on top was corroded into a big green mess and the mag was pretty rusty. I got excited and cleaned it up in a diesel bath, WTF it still works!
whenever I hear people say they can fit 32 rounds into a 30 round magazine I always assume that's a failure of magazine design that lets the spring compress too much
Another engineer here. I agree in theory, but I also had 3 x39 pmags that I left loaded for ~3 months and now they don't reliably feed the last 2 or so rounds, so YMMV. At the same time, after having a 19 mag loaded for nearly a year and a half it still functions flawlessly.
Thanks, I'll just keep them loaded. You explained it very well (not that I understand it all but, If it does not work get a new one) is the best response to this debate I have heard. Thank you.
When I got out of the police academy I used to download all my duty mags on my off days to “let the springs rest.” I did that for a couple years. Though it didn’t take long to go from every weekend to every few weekends. I got tired of getting dressed on my Monday and realizing I’d forgotten to reload my mags. Now I have rifle and pistol mags that other than range days have stayed loaded for years. I mean if I’m storing ammo for who knows how many years for the apocalypse or something I won’t store it in loaded mags. Mainly because I’d rather spend money on more ammo than extra mags just to sit around loaded.
I have done long-term experiments with several different magazines. Glock mags from the Gen 2 Era were the only ones that I had sufficient creep that they induced malfunctions. That took about 15 years of continuous loading. I have had STANAGs loaded for close to 25 that still function correctly. Haven't had nearly that much time on SIG P226, 5th generation glock or Pmags, but thus far no issues with long term loading.
@@BrassFacts If you worked hard enough in engineering school, you’ll find the 9-5 relaxing in comparison. I had trouble believing that from my friends, but it is so true.
@@BrassFacts Work is as final as life, which is still finite. You can’t truly experience life without work, or vice versa. God willing, you’ll always work, the task is the only thing that changes. Keep your work ethic from school and apply it to everything else. If you’re working for yourself and your family under the authority of God, it will be indistinguishable from joy in abundance.
I stopped worrying about this ever since I found out that there are original medieval swords that still have their spring temper. Turns out, we're actually pretty good at this sort of thing.
Hope your exams went well. I had planned on going to Colorado school of mines for materials. Life happened and that didn't, anyway awesome video. Its good to have someone put out context.
shot rounds out of a magazine that was loaded for at least a decade. but i also rarely used it of course. it was a mag pul mag. thank you for the video. good info.
Holy shit, fellow MatSE here. THANK YOU for putting some of the normal BS about mags wearing out. Also mad at you for putting up a stress stain curve and triggering my PTSD from college XD
It wasn't explicitly stated but to achieve severe creep deformation you need the recipe of high operating temperature, stress, and time. Hence why the 50 year old mag will work less effectively. Also as a follow-on you're probably more realistically going to have your spring primarily fail due to corrosion which accelerates the deterioration of the elastic strength. Another way to view it is that the fatigue strength is based off the number of cycles, temperature, and the load magnitude experienced.
yeah, I wanted to keep it super simple. I cut a lot out like critical crack growth in the spring, or feed lips, and more. Figured this surface level view would be far better. and if I wanted to I could always do more videos. Fundamentally I just want to explain that, cyclic fatigue is probably the largest contributor behind just loosing the mag or blowing out the feed lips.
I like to think of fatigue more as the higher stress state (still below yield) of a material allowing dislocations to jump or move in small steps towards some imperfection in the material or wherever localized stress is the highest. And over many cycles of this low stress state, the dislocation conglomerate on some stress concentration point and eventually form a crack. This is effectively decreasing the area so while the load may not be increasing, the stress is, especially locally. And this worsens very quickly as the crack forms and propagates.
Yea I have about 5-6 pmags that have been left loaded for about 14-15 years. I fired one mag from this bunch a few months ago. Zero issues. Spring still feels strong. Everything else I read about this confirms my results too. Your vid and others say dont every worry about it. These mags that have been left loaded wasn't intentional either, just a result of time flying! lol
Great explanation. I've been curious about this. Bringing your engineering background into play more often might be a good addition to the channel. Maybe ease up on the self deprecation too, you make good serious content that IS interesting
I almost always leave my mags loaded. Most of my Gen 2 Pmags feed lips have expanded slightly. Only to the point of an empty mag not free-falling from my AR. Nothing that’s prohibited function yet, and a few of my mags are easily 5 + years at this point, fully loaded. Haven’t had my Hex mags long enough to know yet.
You should take a look at your feet lips under a magnifying glass and check for cracks. The can be difficult to see with the magazine loaded putting outward pressure on the feed lips and they can be very difficult to see with the naked eye
I leave mine loaded to 29/30, so that its easier to load on a closed bolt, and to reduce wear on the spring from leaving them loaded. This is probably not needed, and based on Fuddlore.
I have noticed some hairline cracks on both G2, and G3 pmags. Most of it seems to be G2, but I had a G3 fail after a shockingly low time frame, and low usage.
Whaaaaat??? You're an MSE too? No way! I'm a materials/metallurgical engineer. I particularly work on wear/failure analysis and on wire/spring and fastener metallurgy. Your magazine springs are usually going to be ASTM A228 music wire or equivalent. Something like ASTM A877 chrome-silicon wire would have significantly higher fatigue and creep resistance. We use some wire grades with nickel and vanadium too, which can go even more cycles at higher temperatures. Also, I'm in the Midwest. I thought you were out in Utah or Oregon? Somehow I missed this one two years ago. If you're still interested in Midwest employment, I might be able to make a connection for you.
A youtube channel by the name of deltaleader71 made a video about his mags that were loaded for 18 years in his safe, just checked and the video is still there. His springs measured shorter than a brand new spring by almost 2 inches but functioned fine. I believe he even said that the new spring was purchased at the same time as the ones in the stored compressed mags, so they were the same brand.
Term is "work harding." Took me a while to get to this video. I thought I sensed some engineer speak in your videos. Myself, 28 years as a Mech Design engineer. BSME (after the Army). And btw- John Deere is hiring. Deere has a ton of openings in the midwest, if you are still looking.
While I know I won’t be damaging my mags by leaving them loaded (except a few no-name brands), I keep my stored 30 round mags at 20 rounds and my 20 round at 10 rounds. This keeps enough rounds in the mags that I can use them if I need too, but one stripper cli will fill them all the way up if something BIG is going down. My carry mags are usually downloaded by one or two, but this is just a holdover from the military where they told us to load 28 in a 30 round magazine.
TLDW: Loading and unloading your magazines wears them out not leaving them loaded. Which is 100% correct but for the love of God, if you leave Magpul mags loaded long-term use the dust-cover that came with them. It isn't a dust cover, it ever-so-slightly loads the spring to remove load from the feed lips. The springs can handle that load indefinitely, but the polymer can't and those feed lips can spread far enough to not fit or even empty itself.
this is a great comment for those who are unaware. pmags are great, but that polymer will deform over time so use the 'dust covers' that they (should) come with. I personally stick with the ol' reliable stanags.
Ayy bro an MSE! Y'all are rare haha. I just graduated as a MechE with a concentration in Materials. Always fun to apply what we learn in our courses to our hobbies and lifestyles. Good luck on the job search brother!
I would worry more about the wear on polymer feed lips than a spring. I’ll still always store loaded but just curious if it would wear on the poly fees lips
This does not account for manufacturers failing to install a spring to the engineered specs. I would suggest firing your duty mags a couple cycles to confirm reliability and if you store them full (you should store some of them full), maybe check reliability every couple years. But if you train like Brass Facts (frankly who has the budget for ammo?), you probably cycle through them fast enough for long term issues to not show up.
I think some people also leave out any over-built nature of springs which will take into account springs will generally take a "set" but still have enough pressure to feed with that "set."
Creep becomes a significant factor at about 35 percent of the materials melting point on an absolute scale (Kelvin or Rankine). So steel with a melting point of 2000F (2460R) will start to suffer from creep at 400F (860R). This is why materials with lower melting points can suffer from significant creep at room temperature. You need to look at an absolute scale.
For those of us who can't legally get new mags, I'm more concerned with eventual feed lip deformation or cracking on old plastic pre ban mags. Got any data or experience with that?
Good overview here. I actually have several Gen 2 Pmags loaded up to 30 rds of Wolf Gold 55g, loaded back in ~2014 ish. They are tucked away in a bin but once a while I'll check for any cracks on feed lips or down the spine, so far nothing. To be honest at this point I'm not sure if I should just keep them as a long term observation project or just test them out this Xmas.
This is always an interesting debate to me when there are literal videos online of a ww1 or ww2 or interwar i cannot remember 1911 being fired without malfunction. Its mags had been loaded the entire time too. I'd be more worried about plolymer ar mags deteriorating before the metal springs inside.
Late to the game, but I live in the frozen tundra of ND and commonly leave mags in my truck during the winter. Had a hex mag straight up explode, split right down the spine (brass ammo for reference). No issues with aluminum or Magpul. Sincerely, A fellow ME
I will say some polymer mags will have severe creep issues if left loaded for a year or 2. I actually have one that did not loose a single round but the feed lips spread so far it will not fit into any firearm.
Every time I pull my magazines apart to clean them I always stretch the spring a little bit but from what you’ve explained I’m probably doing more damage to the spring that way then helping it would you agree
if people are worried about duty cycles of their mag springs, just tell them about valve springs in their engines in comparison and ask if they also worry about them
Saw a guy pull out 25 years of loaded mags and shot it, zero issues. Other engineers state that the spring wears down more from going up and down, not being in a compressed position. 25 years is the proof, don't worry about it
Magpul literally sells a 3 pack of new springs and followers for 6 bucks for old GI mags. As long as the actual shell isn't ruined you can just buy these things and essentially have a functionally new magazine for 2 bucks.
Factory Scorpion mags are the only ones I’ve had issues with. A feed lip broke off under pressure and spewed its 20 rounds onto the floor of the gun safe.
Magpul Pmags wear out crazy fast if not used properly. Once a year at annual qualification we inspect all dept issued mags and usually find 5-10 with hairline cracks on the feed lips and 5-10 with bulging sidewalls. 90% of the time when we find damaged mags they have been overloaded to 31rnds and left that way all year. Almost impossible to notice the damage without calipers for the bulging and a magnifying glass for the feed lips. We tested a batch of damaged mags a few years back and found that the ones with hairline cracks on the feed lips would completely break shockingly easy when dropped fully loaded on concrete. Seeing so many break at work has caused me to start buying mostly lancers for personal use and leave my Pmags loaded to 29rnds or completely unloaded when just being stored. Also if you're paying $15 for pmags in 2021 your paying way to much. They frequently go on sale for $10 each and every once in awhile as low as $7.99
yeah, if you overload a mag you'll be likely exceeding the feed lip yield strength, or close. Add a jolt, and you'll for sure exceed it. $15 bucks for gen 3s. Gen 2s are a lot more cheap, but have issues.
@@BrassFacts what issues? My dept. Specifically went with Gen 2 because we had issues with Gen 3 mags failing to seat properly in the slightly flared mag wells our AR's have
@@PracticalTacticalSheepDog yeah pmag are designed for specific lower dimensions. The issues are mostly follower path design related, the over insertion tab, and some others I've long since forgotten my g2 mags wear out noticeably faster both at the joint that connects the feed lips (base of the U shape) and the older G2 followers round out in dry fire in like 6mo-1 year
Your wrong on one thing. They have found several world War 2 mags loaded and they fired, unloaded, and studied them and found not noticeable or measurable difference between the springs and new ones. I cant remember exactly where but I remember at one point reading a study estimating that it woukd take 400 years of stored compression to add at maximum of 1% reduction from creep and that its more likely season temperature cycling woukd be the majority cause of damage.
Great info. It would be interesting if you could do something similar to pistol frame material. Steel, aluminum, polymer. I've heard aluminum frames might have a 30k life, and some competition shooters breaking their glock frames. Possibly why HK uses a buffer system in their hammer fire guns.
really hard to say, I've been considering metal mags vs plastic mags vs pmags (similar concept) But the issue is, I no longer have acess to a tensile testing machine, and the data on pmags or other types of plastic mags are not widely available. Specifically tensile strength, + UTS, and material composition. I suspect pmags are nylon reinforced with fiberglass (nylon 6) but that's to vague to make a vide on. Same issue with metal vs plastic guns. I would have to speak extremely vaguely without data.
That makes sense. Every manufacturer might use different materials, alloys and what not. Personally, I wouldnt mind a general video about the different frame materials, and why they end up breaking.
I would appreciate this. I could be wrong, but from what I know, proper polymer frames will almost always outlast aluminum frames. Aluminum work hardens, becoming brittle, and eventually cracks. Polymer flexes and disperses the energy much better, and is a much better frame material for handguns.
People have shot ammo from 1911 and m1 carbine mag that have be loaded sense ww2 and even ww1 with out a issue. Springs and mags have come a long way sense ww2.
>5.56 won't even be around in 50 years They probably said that during procurement in 1972. I had a mag my uncle gave me as a kid, that he had from his service in Vietnam, it's older than I am, I have since rebuilt it, possibly several times. At some point in the mid 2000's I was at the range, and I put a stripper clip spoon on the mag, put a stripper clip in, and jammed those rounds in. With each round going in, a coil of the spring snapped and it collapsed a little more. The whole spring just turned into a "half racetrack". So that spring was probably 30-ish years old at that point, still had the original black follower. All of the anodizing is gone, but I put a new magpul follower, fresh spring, and a fresh floor plate (wanted a ranger pull). Still using it today.
