How long is .22 Rimfire Ammo good for?

August 7, 2010 by  
Filed under Trail Boss Articles

If you are like me and like to shoot, you will find yourself with a huge supply of .22 ammo for a multitude of different reasons. It is not unusual for me to buy a brick or two on a regular basis and more if the ammo is on sale. Because of this I wind up with an abundance and some of it needs to be stored. Having a good deal of .22 ammo around is never a bad thing. I can always find a reason to grab one of my favorite rifles or pistols and head out for a day of practice, hunting or plinking. When storing .22 rimfire ammunition it pays to spend a little more to buy quality ammo.   I have stored .22 rimfire ammo up to ten years with no ill effect. Buying quality ammo avoids risk of misfires or split cases upon firing years later. I have frequently experienced misfires, split cases, dried out lube, corroded or oxidized bullets, poor accuracy and generally poor performance with older .22 rimfire ammo. This occurs mostly with cheap promotional ammo, and seldom  with name-brand, premium stuff.

I shoot a lot of .22 rimfire ammo for practice to keep from shooting out barrels in my service rifles and using up more limited, expensive to replace stocks of centerfire ammo. Most of my .22 practice is from target pistols indoors at 25 yards and rifle firing outdoors from 50 to 200 yards.  Firing a .22 bolt rifle outdoors at 200 yards is a good simulation for long-range .30 cal. rifle practice. So, I want better than “minute of beer can” accuracy. I desire 2-inch groups at 50 yards from a target pistol, the same at 100 yards firing prone from a bolt action target rifle, and in proportion to 200 yards. Most inexpensive promotional ammo cannot deliver this. Selected lots of CCI Blazer do, and the vast majority of CCI Subsonic HP and Mini-Mag do so with no trouble. Of course match ammo does much better, but I don’t care to spend $500 or more a brick for it.

Prior to WWII most rimfire ammo was made by the cup-and-draw process from 95/5 gilding metal. Before about 1970 the higher priced brands, such as Winchester Mk. III, Lapua and Eley used “red brass” having a higher copper content. Rimfire cases were gas annealed and not subject to age hardening. The only thing which suffered with age was the bullet lube, grease, which simply dried out. A light wipe with an oily patch or white lithium grease immediately before shooting fixes that.

Today most .22 rimfire ammo is produced by progressive die stamping from sheet brass, typically using 90/10 alloy. Main-line, name brand ammo is stress relieved, but much cheaper stuff is not. Work hardening results from cold working sheet stock to form the base, which makes the rim which contains the primer mix harder and stronger, and more difficult to deform by the firing pin strike, so that rounds are less sensitive, and you get more misfires. After long storage of more than 10 years you can expect increased misfires unless your firearm has a well placed, very strong firing pin indent. Even so, you will still get one or two in a box.  Sometimes in old ammo you may experience case splits through the rim radius, which cause a puff of smoke and release of gas into your face. So wear glasses always when firing any gun.

Cheap plated high velocity ammo has little or no lube on the bullets. In cheap ammo this plating is only a thin copper wash which is not adequate to withstand abrasion by the rifling. Dry wax bullet lube used on cheap rimfire ammo is most often applied in a thin water emulsion, prior to bullet seating. The knurling on the bullet is applied on the crimping machine. This means that the knurling tool cuts through the lube film, exposing naked lead to rub on the bore. This broken lube coating becomes brittle with age and may flake off in a powdery residue. Dry wax lube on current Winchester and Federal ammo does not waterproof the ammunition.

CCI Mini-Mag uses a heavier gilding metal cladding applied in a barrel plater to the pre-formed slug prior to final sizing and pointing up. This is heavy enough not to be abraded away by the rifling. While the cladding is sufficiently thick as not to require additional lubrication, CCI .22 LR rounds are also fully waterproofed by dipping in 160-degree paraffin lubricant, which is applied to cover the case mouth after bullet seating and crimping. The same hot paraffin dip, waterproof process is used on Green Tag, Standard Velocity, Subsonic Hollowpoint and Blazer.  To my knowledge these are the only currently available .22 rimfire ammunition’s which will stand complete water immersion and are reliable enough for survival kit seat pack use.

I am currently using stocks of CCI Standard Velocity .22 LR ammo which pre-dates the introduction of Green Tag. Most of this ammo dates from the Vietnam war period to the mid-1980s. It is fully reliable, accurate and as uniform as fresh ammo. This ammo was repacked and stored for years in M2A1 military ammunition cans just closed up with normal ambient air ever since I got it.

Older paper-boxed Eley, Winchester, RWS and Lapua match ammo having greased bullets stored in the same manner sometimes suffers from the bullet lube drying out or bullets oxidizing. If this oxidation does not increase bullet diameter so as to preclude chambering, such ammo can be salvaged and remains suitable for precision use when the “frosty” appearing bullets of individual rounds are wiped, at the range before loading, with a cotton patch LIGHTLY wet with pure USP mineral oil, to then be shot immediately. This method can also be used to salvage cheap brands of .22 ammo having dried out lube or oxidized bullets, but I find generally that the cheap ammos also have undersized bullets of .221-.223 diameter, which shoot poorly compared to the brands which are most accurate having bullet diameters in the range of .2235-.2250.

The key to ensuring rimfire ammunition quality, is well made cases, properly stress annealed, which won’t age harden, with uiform distribution of primer mix, bullets of sufficient diameter, not less than .223″, and good lube. Remington Standard Velocity .22 ammo made at Brideport, CT in the 1970s or Winchester white box made about the same time in New Haven, CT is still good, as is regular commercial production CCI ammo from the same period. But I have not had the same experience with cheap, so-called “promotional” ammo sold at discount stores. I get a high percentage of misfires, dried out lube and poor accuracy after about 10 years. I don’t depend on such ammo except for recreational use. Buy only the very best ammo if you do not plan on shooting it right away. It will cost more, but it will work in 25 years.

My old stocks of ammo back from  will soon be gone. I am buying a new supply of CCI Subsonic HP, CCI Blazer, and Mini-Mag to replace it. CCI Blazer seems to be the best bang for the buck for recreational plinking and practice ammo. It functions well works in everything, is accurate and has good shelf life.  I bought a case each of CCI subsonic HP and CCI Mini-Mag HP for hunting ammunition.  I also salted away two bricks of Eley Standard Pistol for each pre-war Colt Woodsman and High Standard just because I like how it the combination of lube and powder smoke smells! My friend Harry Archer used to call it “perfume powder.” There is really nothing like the aroma of Eley on a crisp fall morning in a hardwood forest. Anticipation of fried squirrel!

Remember protect your ammo from extreme heat, and moisture. Store it on a shelf off the floor.  Keep it out of damp basements extremely hot attic, outdoor garages or in the car trunk during summer months.  Keep the ammo in its original manufacturer’s packing then store those in a GI metal cans or similar device.

C.E. “Ed” Harris

C.E. “Ed” Harris is well known to readers of American Rifleman, the Gun Digest and the Cast Bullet Association’s Fouling Shot magazine.During 12 years on the Technical Staff of the National Rifle Association he was a consultant to numerous military, law enforcement and firearms industry organizations and was officially commended by the U.S. Marine Corps Development Center, Quantico, Virginia for  expert technical assistance provided during the Development and Operational Testing of the M16A2 rifle. He is a graduate of Virginia Polytechnic Institute, holds the Federal Emergency Management Agency’s Professional Development Certification in Emergency Management and for 22 years he has worked for local government in Northern Virginia.

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4 Comments on "How long is .22 Rimfire Ammo good for?"

  1. Steve in Merritt Island on Sun, 8th Aug 2010 2:11 PM 

    Ed,

    Excellent article (as always!). I see your praise for the CCI Subsonic HP, but have yet to find it locally unfortunately. The dealer over across the river in Melbourne (FL) does have generous stock of the Remington 38 grain Subsonic HP. A while back I had read, and acted on your comments about buying greased, as opposed to plated bullets. For the “average Joe” (i.e. me), is there a big noticeable enough difference that I should choose the CCI instead? The only .22s I shoot anymore are my Winchesters M69a and M9422, along with my K-22 6″ and Ruger MkII HB. I don’t compete in matches. This would be just to augument my supply of CCI SGBs, the aforementioned Remingtons, and assorted Win. lead HPs.

    Thank you for your ongoing, unselfish efforts to educate us all. I find myself combing ShilohTV on a regular basis searching for anything new you have put out for us. It is deeply appreciated.

    Steve in Merritt Island

  2. ke4sky on Tue, 10th Aug 2010 6:34 AM 

    Early batches of Remington subsonic HP used a black waxy lube and shot fine. Recent batches I have tried both of Remington subsonic and standard velocity Target ammo appeared to be lubricated with dry graphite only, which shot poorly and leaded severely. If you cannot feel wax when you scrape off the lube film and rub it in your fingers, don’t buyt the ammo.

  3. 007kgb on Mon, 14th Nov 2011 12:24 PM 

    RE: CCI .22 LR rounds are also fully waterproofed

    Here’s the response from CCI:

    Our CCI rimfire is not waterproof.

    Linda Olin
    CCI/Speer Technical Services
    2299 Snake River Ave.
    Lewiston, ID 83501

    To: cciexpert
    Subject: CCI Ammo – Ask the Expert Form

    I have read that all CCI .22 cal ammo is waterproof. Is this true? Are there specific rounds that are water proof like the Stinger or the Mini Mag or are they all waterproof?

    007kgb

  4. shilohtv on Tue, 15th Nov 2011 1:26 AM 

    For the most part they all are unless they get soaked for a long time.

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