I purchased a few used surplus mags that need a good cleaning. What should be used to clean them up inside and out? Should a light oil be used afterwards to prevent rust?

 

a good wipe down with WD-40 to clean it, then wipe off the WD-40



If using CLP ok to leave a thin coat



Hard to muck up an AK mag



Got some years back from Sportsmans Guide and they all were caked with cosmoline

There is an unknown white residue on the inside of them, they're pretty nasty inside. I'm wanting to clean them up somewhat.

Is it sticky, like dried up axle grease? If so, that probably is cosmoline. I bought some East German mags a few years ago that had a coating of cosmoline, inside and out. I ended up using mineral spirits and a brush to get it out.

I was told "long ago" that a overnight soak in some diesel, followed with a brief scrub will remove cosmo pretty well, plus it won't 'provoke' rust like using water will.

BIGGER_HAMMER

the mags were used and if it was cosmoline, it was on there for a long time. I disassembled them and gave them a good scrub with Dawn dish soap. They look much better now:)

Wipe down to get the major crud off, boil in hot water to get the rest, maybe use a toothbrush to clean excess crap.  Then dry and wipe with CLP.  I would leave them on some wax paper and repeat the CLP wipes every other day.  Be pretty in a week.  Then just wipe any excess CLP off and enjoy.

Buy a $5 tin pan at Walmart that you can throw on the stove.  I have several for when I need to clean.
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Good luck!

If I'm doing a lot, I'll boil them in a disposable aluminum turkey-roasting pan. Hit them with a mag/bottle brush or some rags on a stick to wipe out the excess cosmo. They'll be hot so they'll dry quickly. I'll then hit them with some Hornady One Shot to protect the steel from corrosion.

If I'm just doing a couple, I use Hornady One Shot along with a brush and some rags or old t-shirts. That stuff does a very good job of dissolving cosmoline and it leaves a dry, protective, lubricating film behind. I'm in love with One Shot and I'd use it for everything were it not so expensive (relatively speaking), which is why I use boiling water if I'm doing a large number of mags.

Non-chlorinated brake cleaner is also very good at removing cosmoline (and just about anything else) and it's very cheap. It will strip all the oils out of the steel, however, so you'll need to apply some form of protectorant afterwards. Also, if you value your brain cells, only use brake cleaner in a well-ventilated area, preferably outdoors.