If more people had the opportunity to attend armorer training put on by some of the major gun companies who train LE/Gov agencies, they'd learn that the common recommendation is that magazines are not lubricated, and remain dry inside. When a fill-in-the-blank answer to a test question about 2 places where lubrication ought
not applied has the
magazine as one of the answers, it sort of tests whether the student was listening.
One company has started warning armorers that if they use a dedicated solvent for cleaning, make sure it's completely removed from metal surfaces before applying a dedicated oil/lubricant, to avoid the combined products producing a sticky mixture that can impair normal feeding and functioning. (Hint: Gun companies may begin to include warnings against some practices when they start hearing complaints about problems reported by their LE users, and they figure out how the users may themselves be causing the problems.
)
Sure, LE users can (and have) often experienced and reported issues when magazines are contaminated during normal carry and training (think dropping prone on dirt and sand surfaces), have accumulated dust, wind-blown sand and other debris get inside the magazine bodies through "witness" holes. I've also seen magazines in both LE off-duty weapons and private owner CCW weapons exhibit accumulated dirt, grunge, lint and what can only be described as "congealed goo" interfere with the normal feeding and functioning of their magazines during live-fire exercises.
I've wiped bare metal spring coils (meaning if not painted or otherwise coated) with a
lightly dampened patch/rag using one or another CLP to remove fouling, but then wiping off any residue using a clean/dry patch/rag, to avoid introducing contamination to the inside of the magazine (and the ammunition later introduced). Ditto a fouled or dirty magazine body.
Magazines are
assemblies, but they're generally assemblies that don't require lubrication of the "moving parts". Sure, periodic inspection and normal maintenance to prevent oxidation of the metal surfaces is one of the responsibilities of the user/owner. If mags are subjected to contamination, like being exposed to inclement weather, dropped into water or other liquids, subjected to humidity and temperature changes that might produce condensation, then it may be wise not to wait for the "next" scheduled periodic inspection to come around, but to inspect and care for them as soon as possible after the occurrence.
An example of this was when I was working a range session out in some nasty cold and rainy weather, and I was literally having to pour water out of my magazines at various times, as the loose ammo I was loading into the mags was being pulled from large jacket pockets that were filling with rain water, wetting all of the ammunition. The heavy rain was pouring onto and into the mags as I was holding them in the heavy rain while loading them with fresh rounds throughout the day. At the end of the day I disassembled and wiped out all of the mags, carefully wiping them out/down and leaving them clean and dry before reloading them. (Ditto the saturated gun, of course.)
One time I had an agency weapon (stainless steel pistol) brought over to me from another agency (they didn't have an armorer at that time) because the issued user had forgotten to tell anyone that he'd dropped the weapon in sea water ... a year prior.
The magazine springs (and some other, smaller springs) had developed oxidation afterward, eventually causing functioning issues.
I used to discuss duty weapon maintenance and repair issues with an instructor & armorer who worked for an agency where dust-blown sand (of the fine grit variety) managed to get inside duty Glock pistols and magazines on a regular basis. He mentioned that fine sand was introduced inside the mags carried on uniform gun belts, entering via the witness holes exposed above the carrier body. One time he told me he'd even experienced a trigger/connector problem, and had discovered a bit of hard sand/grit had lodged itself between the trigger bar tail and the connector. He described the symptoms as an increasingly heavier trigger pull that day (on their training range), right up until the moment the trigger couldn't be pulled far enough back for the weapon to fire.
As a firearms trainer (and armorer) I've seen more instances than I care to remember of watching people, during quals and training, drop their magazines onto the sand surface of our range. Sometimes they could reload and continue the mags without problems, and sometimes the sand managed to enter the mag bodies to a degree sufficient for the next magazine load to produce feeding issues. I saw one poor fellow drop one partially loaded mag (major maker Euro gun) onto the damp sand, pick it up and wipe/blow the crusted sand off, and then reload the weapon to continue shooting. He managed to feed/chamber and fire one round ... at which time the weapon completely seized up and stopped functioning. It couldn't even be manually operated to resolve the stoppage.
Folks, magazines are at the very heart of normal feeding and functioning in magazine-fed semiauto pistols. They're assemblies that are made of parts, and those parts deserve some attention to condition and cleanliness, and parts can experience normal wear, as well as damage.