If you store your firearms and an emergency on-hand cache of ammo in a gun safe, remember that the material used in the fireproofing holds a small amount of moisture and is also slightly corrosive. You need to do two things on a regular basis. Open that motherfucker up whenever possible and let it air out and keep something inside to absorb that moisture whether it be a plug in module or good ol' silica.
Myself, I keep my safe open whenever I'm home. I always keep a pistol handy but my shorty and my 308 stay in the safe during the day - the shorty goes to bed with me along with my dog and an LED flashlight.
But I'm getting off subject here.
What I use is a mini-dehumidifier (Model 365) made by Remington and I believe it ran me about 35 bucks at my local gunshop. It measures about 6"x6"x1" and has silica beads that change color when they've absorbed moisture. When they turn pussy pink, I plug the unit into a socket for about 12 hours and it dries them out and back into the safe it goes.
Okay. Just because I have that in there doesn't mean that I forget about checking for corrosion on guns (I bet Derek cringes every time I refer to a firearm as a gun) that I don't handle regularly. At least once a month, haul the motherfuckers out, inspect them inside and out under a bright light and maintain them. If you start to see signs of corrosion, knock that shit off with some ultra fine steel wool, give the weapons a good cleaning and oil them down. More about oiling them in a bit.
If you've got gun wrap on your hunting/tactical weapons to camouflage them or to provide a sure grip, unwrap them and check them. That shit will hold moisture and fuck up that barrel and receiver for sure. Wrap only costs about 12 bucks a roll, figure that into your monthly budget. You should be changing that anytime the seasons or your shooting location changes anyways.
As a side note, I know a guy that went bear hunting up in Alaska and he got rained on every fucking day. On the advice of his guide he wrapped the gun, then sprayed the wrap with WD-40. When he got home 2 weeks later he unwrapped it and there wasn't a speck of rust on it.
Personally, I wouldn't do that because of the odor, but that's just me. If you've read my coyote hunting posts you know how I am about wind and scent.
Ammo - keep your home cache in ziplocks or food-saver bags. I keep my reloaded hunting ammo in bags of 12 and grab-and-run shit in bags of 50. If you reload you need to take an extra step and I'll explain why and then give you a solution.
Every time you punch those primers out you enlarge that primer hole just a bit. What you should do to keep moisture from seeping in and killing the primer is to take some of your sweeties' clear nail polish and carefully apply a very thin coat around the edges of your primer. Do not - I repeat - do not cover your primer with it as this may cause a misfire when your firing pin fails to penetrate the polish and bounces off your primer.
Rotate your home-cache ammo occasionally just to be safe.
Now let's talk about your automatic handgun.
Field strip that motherfucker down at least once a week and clean it. Even if you haven't shot it, at least take it down and inspect it, wipe it down and re-oil it. I carry a Colt Officers' Model in 45 ACP (God Bless John Moses Browning) and my weekly routine is to strip it, wipe it down and lightly oil it. I apply a film of oil and gently wipe it off. Before I reassemble it, I put one drop of oil on each rail on the frame, then I put it back together and cycle the slide a half dozen times. Then I strip the slide off again, wipe the oil off and put 'er back together. I don't want too much fucking oil on my weapon because I live in a dusty climate and oil attracts dust which gums the fuck out of it. One of the main reasons for Colts jamming (in my experience) is lack of lubrication. The friction causes the metal to gall and that causes burrs and slows down the action. Lube your fucking slide, folks. An added benefit is that after thousands of rounds, you'll still have a tight frame-slide mate. Yes, you can wear out an automatic..... Lubrication slows that down.
Okay. Every 500 hundred rounds, strip your auto down as far as you can and inspect every fucking piece of it. Seriously, I take my Colt down completely - trigger assembly included - and check everything, paying particular attention to the firing pin, sear, disconnector and recoil spring plug. And yeah, I use a magnifying glass when I do it. I do not want a cracked firing pin in my lifesaver, nor do I want my plug to give way and cause my springs to go flying downrange.
Thoroughly clean every part. Apply a light film of oil to every thing except the mating surfaces of your sear and disconnector.
This is a labor of love, godammit, and it may save your fucking life. Not only that, but it will make you understand your weapon so much better.
Replace all your springs occasionally. They do fatigue. If you have a Chinese made weapon or magazine, replace the springs immediately. The quality of Chinese steel is outragiously good but their springs fucking suck.
And speaking of springs and magazines, how many of you maintain your weapons but ignore your magazines? An automatic handgun ain't worth a fuck if it fails to feed because of a broken magazine spring that you failed to notice, right?
When you clean your weapon, unload your magazine and disassemble it. Depress your follower, stick a nail through one of the holes in your magazine, shake the follower out being very careful with it, and pull the nail out. Then snatch the spring off of the floor before your dog grabs the motherfucker and runs off with it.
Clean it with solvent, give it a light coat of oil and reassemble it. Inspect your ammo, wipe it off with a clean, dry rag (no oil) and reload it.
Go down and buy a couple of extra magazines. When you change your fire alarm batteries and reset your clocks, change your magazines out. Give the motherfuckers a break and they'll last you a lifetime and you can always depend on them.
Okay. Hope this helps.