How Long is .22 Rimfire Ammo Good for?
(c) 2014 – Ed Harris
The last year or so .22 rimfire ammo has been scarce on dealer shelves. So I’ve been digging into old stuff I didn’t remember I had. So is it still any good? Or is it worth more as a collectible?
If buying a quantity of .22 rimfire ammunition
for long term storage of more than ten years, it pays to spend a bit more to
buy quality ammo. Doing so mostly avoids
the risk of misfires or split cases which could occur upon firing many years
later. In my NRA
days I have experienced misfires, split cases, dried out bullet lube, corroded
or oxidized bullets, poor accuracy and erratic performance with .22 rimfire ammo which was more than 20 years
old and stored in a damp basement. This seemed to occur more often with cheap
promotional ammo than with name-brand, premium stuff.
Until a few years ago I shot lots of .22 rimfire for practice to avoid shooting out barrels in my center-fire rifles, instead of using up more expensive to replace center-fire ammo. Most of my .22 practice is 50 foot indoor gallery pistol or firing rifles outdoors at 50 or 100 yards, much less often at 200 yards, but firing a .22 bolt rifle prone outdoors at 200 yards is a good simulation for long-range .30 cal. rifle practice.
I want better than "minute of beer
can" accuracy. I seek 2-inch
groups at 50 yards from a target pistol, the same at 100 yards firing prone with
a bolt action rifle, and in proportion at 200 yards. Bulk, inexpensive “promotional”
ammo seldom delivers this. Selected lots of CCI Blazer will, and so does the
majority of CCI Standard Velocity, Subsonic HP and Mini-Mag. Match ammo, of
course, does much better, but I don't care to spend up to $500 or more a brick these
days for “Eley Good Stuff.”
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 also gas flame annealed and not subject to age hardening. What did suffer with age was the bullet lube, or 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. Name brand ammo is stress relieved, but the cheapest, imported stuff probably isn’t. Work hardening results from cold working the sheet stock to fold the base. This makes the rim which contains the priming mix harder, and more difficult to deform by the firing pin strike, so that rounds are less sensitive, and you may get more misfires. This most often occurs in guns which are dirty and gunked up from long term plinking, further weakening the striker blow. In cheap brands you get occasional misfires even with new ammunition. After more than 10 years you can expect increased frequency of misfires unless your firearm has a properly placed, strong firing pin indent. Even so, you with older ammo you may still get one or two in a box. Occasionally old ammo experiences case splits through the rim, causing a puff of smoke and release of hot gas into your face. So always wear glasses!
The cheapest plated high velocity ammo has little or no lube on the bullets. The plating is a thin copper wash usually not adequate to withstand abrasion by the rifling, especially in older guns which may have pitted bores from exposure to moisture or corrosive primers . The dry wax bullet lube on most rimfire ammo is applied via a water emulsion, prior to loading and bullet seating. The knurling on the bullet is applied on the crimping machine after the bullet is seated. So the knurling tool cuts through the lube film, exposing naked lead to rub on the bore. If the lubricant readily flows under pressure, this is not a problem. But if the coating becomes brittle with age and flakes off in a powdery residue, you will get leading.
CCI Mini-Mag use a heavier gilding metal cladding applied in a barrel
plater to pre-formed slugs prior to final sizing and forming. This is heavy enough not to be abraded away by
the rifling and is sufficiently thick as not to require additional lubrication,
but CCI rounds are also waxed to prevent corrosion of the plating. A hot paraffin dip, lubricating process is
used on Green Tag, Standard Velocity, Subsonic Hollowpoint and Blazer. I have found that CCI ammo has wonderful shelf
life. I am now using CCI Standard
Velocity .22 LR ammo purchased in the mid 1980's. It is fully reliable
and accurate as fresh ammo bought at Camp Perry last year from Champion’s Choice.
Older paper-boxed Eley, Winchester, RWS and Lapua match ammo having greased bullets may suffer from the bullet lube drying out and bullets oxidizing. If the oxidation does not increase bullet diameter so as to preclude chambering, the ammo can be salvaged and remain suitable for practice, and perhaps even for match use, (if you are lucky) when "frosty" appearing bullets of individual rounds are wiped, at the range immediately before loading, with a cotton patch LIGHTLY moistened 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 secrets to good rimfire ammunition are: well made cases, properly stress annealed, which doesn’t age harden, having uniform distribution of primer mix, bullets close to maximum diameter, not less than .223", and stable 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.
I have not had the same experience with so-called "promotional" ammo sold at the “big box” discount stores. When new, you get a few misfires in a box. After 10 years or so you get a higher percentage of misfires, and if the bullet lube dries out and accuracy degrades. Use such ammo soon.
My old stocks of ammo back from "Ruger days" will soon be gone. I am bought a fresh supply of CCI Standard Velocity for paper punching, Subsonic HP for squirrel and CCI Blazer high velocity, for plinking. CCI Blazer seems to be the best bang for the buck for recreational plinking and informal practice ammo. It functions well in everything, is accurate enough for all but the most serious purposes and has good shelf life. But its big shortcoming is that nothing matches the aroma of Eley perfume powder on a crisp fall morning sitting in a hardwood forest in anticipation of fried squirrel!