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Aluminum-cased ammunition has been on the market since the early 1980s, offering shooters an alternative to brass or steel cases. However, many rumors and anecdotal horror stories call into question the safety and reliability of this kind of ammunition.
Find out whether it is safe to shoot aluminum ammo, and learn about the differences between aluminum, brass, and steel cases.
History of Aluminum Cases
The general concept behind the use of aluminum as a cartridge case material is not a new idea. Noting that over 50% of the weight of ammunition carried by a typical WW2-era American soldier comes from the brass composing the cartridge case, military research and development groups have long been searching for solutions to this issue.
A typical .30-06 Springfield M2 Ball cartridge weighs approximately 416 grains, of which:
- Bullet: Roughly 150 grains
- Propellant: About 49 grains
- Primer: Approximately 5 grains
- Brass cartridge case: About 212 grains
Although they are rough estimations, the weight of a brass cartridge case does constitute about half of the whole cartridge’s weight.
In 1962, the Frankford Arsenal Research and Development Group experimented with various aluminum alloys as a potential replacement material for brass in cartridge cases.
Aluminum has approximately less than one-third the density of cartridge brass and about 35% of mild steel. Replacing brass with aluminum would reduce an individual cartridge’s weight by about 30%.
Despite using the best materials available (such as aircraft-grade 7075-T6 aluminum), most of these experiments were focused on military service rifle cartridges.
These cartridges’ high operating pressures resulted in frequent failures (split or burst cases, primer leakages), causing the military to abandon the project.
However, testing demonstrated that aluminum cases could withstand the lower pressures of pistol cartridges with fewer problems, eventually resulting in the development and commercialization of aluminum-cased handgun ammo.
Properties of Aluminum Cased Ammo
Although similar to traditional brass and steel ammo, aluminum-cased ammunition possesses several traits and properties making it stand out from the rest.
Understanding these traits and their pros and cons is essential to determine whether you should buy aluminum ammo.
When comparing aluminum vs. brass ammo, the primary difference is weight.
Aluminum-cased cartridges are significantly lighter than brass-cased or steel-cased counterparts. Although the weight difference may not be as critical to a civilian shooter as it would for military or law enforcement, the difference may be significant when storing, moving, or shipping ammunition.
For most shooters, the most critical trait of aluminum-cased ammo is cost. Aluminum is significantly less pricey than brass or steel, resulting in lower manufacturing costs and, in turn, a lower sticker price.
If you are an occasional shooter and find it challenging to shoot more than 50 rounds a month, the difference may not seem significant. In contrast, if you go through a significant quantity of ammunition per month, the aluminum vs. brass ammo costs comparison quickly falls in favor of aluminum.
On average, the cost per round of aluminum-cased ammo ranges between $0.05 and $0.10 cheaper than brass equivalents. If you shoot 500 rounds per month (about 10 boxes), assuming you save 5 cents per round, you will save at least $25.
Caliber and projectile choices
If you use firearms chambered in pistol or revolver calibers frequently, aluminum-cased ammunition may be an excellent way to shoot and practice on the cheap.
Commercially available aluminum-cased ammunition is only available in a handful of handgun cartridges. Available calibers include 9mm Luger, .45 ACP, .40 S&W, .380 ACP, .32 ACP, .38 Special, .357 Magnum, and .44 Magnum. On occasion, you may also be able to find aluminum-cased ammo in .45 Colt, .25 ACP, .44 Special, and even 9x18mm Makarov.
However, if you primarily shoot rifle cartridges, there is no way for you to benefit from the advantages of aluminum ammo.
There is currently no commercially available rifle-caliber aluminum ammunition on the market, nor is it likely there will ever be any, due to the material’s inherent limitations.
Another potential drawback of aluminum-cased ammunition is the relative lack of choice in projectile types. For instance, virtually all aluminum ammo in semi-automatic pistol cartridges uses full metal jacketed (FMJ) bullets.
In contrast, almost all aluminum-cased revolver cartridges use regular jacketed hollow points (JHP) JHP bullets. The notable exception is .38 Special, typically loaded with lead round nose (LRN) projectiles instead.
You will generally be unable to find aluminum-cased ammo with soft points, defensive hollow points, frangible bullets, or any other projectile.
The same manufacturers typically offer brass-cased ammunition with a more extensive selection of bullet grains and projectile types within the same caliber.
While this is not an issue if all you need is training or practice ammunition, it may be disappointing if you counted on aluminum cases to save money on self-defense or hunting ammo.
Safety and reloading
Factory-made aluminum-cased ammunition produced by a reputable company is perfectly safe to shoot.
If you reload your ammunition, you’ve probably heard you should dismiss aluminum-cased ammunition entirely, either because it’s not reloadable or because the cases are not safe to reuse.
Aluminum cases being non-reloadable is a myth with a partial truth.
Early aluminum-cased ammunition used to be intentionally manufactured with Berdan primers to discourage reloaders from reusing aluminum cases.
Aluminum is more brittle than brass, and fatigued aluminum cases have a high chance of splitting or bursting open upon firing, leading to concerns over catastrophic failures.
This early ammo led reloaders to believe all aluminum ammo is non-reloadable. However, this is no longer true. Modern aluminum ammunition employs standard Boxer primers, and depending on the caliber, may be reloaded.
Although there is no question that you can reload any Boxer-primed casing, the question of whether you should is an entirely different one.
Depending on the caliber, your aluminum cases might be suitable for multiple reuses, or they might split and fail after being reused once.
On average, an aluminum case has a much shorter lifespan than a brass case, and they are more sensitive to high pressures (the higher, the more likely to fail).
If you intend to reload aluminum cases, exercise extreme caution and avoid high-pressure loads. Note that you may still experience case splits with standard and reduced loads.
The Takeaway: Should I Use Aluminum Ammo?
In short, factory aluminum ammo is safe for your guns. If the drawbacks of aluminum ammo are no trouble for you, it is an excellent way to save money on practice ammunition.
Due to aluminum’s relative brittleness, reloaders and shooters using reloaded ammo should exercise caution around aluminum cases.