Whether you should prefer aluminum cases over brass cases or vice versa boils down to your personal preferences.

If you want to pay less for your ammo, don’t mind somewhat dirtier performance, and don’t care about gathering empty shells to reload later on, then aluminum cases have a lot to offer. But if you want cleaner performance and reloadable empty cases – and don’t mind paying more for those features – then traditional brass cases are the way to go.

What Are Aluminum Cases?

Aluminum case ammo dissected with the bullet removed from the casing.

Metallic cartridge cases are traditionally made out of brass, an alloy of copper and zinc. Copper, as you may know, is a semi-precious metal. It also has many uses such as wiring and motors, so a country is always better off for having plenty of copper.

Russia and Germany certainly appreciated the value of copper during World War II. That is why they switched over to loading steel cases during that time, and Russia famously continues to do so to this day. Such cases have several disadvantages, but steel’s significantly lower production cost is the only justification two countries at war needed to substitute it for brass.

For a long time brass and steel would remain the only two viable metals for manufacturing cases. Then along came CCI, an Idahoan manufacturer, which introduced the first aluminum-cased ammunition in 1981. Copper had become more expensive during the previous decade, while advances in technology had made aluminum more affordable. At the time such small aluminum components were rare, but after refining their heat-treatment process CCI developed an acceptably reliable aluminum case.

Today CCI, their subsidiary Blazer, and their sister company Federal Premium all load aluminum cases. We have customers who love Blazer 9mm aluminum cased ammo. The 45 ACP load and 38 special rounds are quite popular too.

But if aluminum is so much cheaper than brass, why isn’t all ammunition now aluminum-cased? Let’s identify all of aluminum’s advantages before touching on all the ways brass beats it.

The Pros of Aluminum Cases

Shooting a pistol with aluminum cased ammo at the range

  • Aluminum is cheaper than brass. This is the truth that brought aluminum cases to the world in the first place. Scrap aluminum costs about 15% as much as raw copper. One brass 9mm case weighs about 0.14 ounces, but that only means 50 rounds of ammo contains 7 ounces of brass (not counting bullet jackets). It’s easy to see how the savings add up when you switch over to aluminum!
  • Aluminum weighs less than brass. This is not a great benefit, but it’s a benefit all the same. Aluminum is approximately two-thirds less dense than brass. You won’t appreciate the difference lightweight aluminum cases make while you’re holding a loaded pistol. You may not even be able to tell the difference between two boxes of ammo. But when you are CCI, which ships out hundreds of thousands of rounds annually, lighter aluminum does significantly reduce your shipping costs. Aluminum-cased ammo’s price tag does reflect this, even if the difference is scanty.
  • Aluminum cannot oxidize (but neither can brass). While both brass and aluminum are capable of corrosion, neither can rust. This makes both metals resilient to humidity and rainfall – something to keep in mind if you’re considering taking the third path and purchasing steel-cased ammo.

The Pros of Brass Cases

  • Brass cases promote cleaner performance. Aluminum is a relatively rigid metal, which impacts its performance in two significant ways. During ignition, the aluminum case’s rim is incapable of expanding outward to form a tight seal around the chamber. As the result an aluminum case allows more propellant gasses to deposit residue inside the action. (This is not a disadvantage as far as revolvers are concerned.) But because brass is relatively supple, cases made of the alloy are far more effective at sealing off the chamber.
  • Brass cases are reloadable. Brass’s superior suppleness also means that a brass case will return to its original dimensions (or extremely close to them) following ignition. This makes brass cases reloadable, whereas aluminum cases will remain permanently deformed and cannot be reshaped back to spec.
  • More gun ranges permit brass casings. Gun ranges like selling the thousands of brass cases they sweep off their floors at the end of the day. It’s not massively profitable, although it’s certainly enough to take the whole staff out for a round of beers. Steel cases may be worthless, but they are easily removed from the sweepings with the help of a magnet. Aluminum cases, on the other hand, are nonmagnetic, which makes life needlessly difficult for frugal rangemasters. As such many ranges prohibit aluminum-cased ammo on their premises.

There you have it! If you’re a casual shooter who doesn’t mind spending more time cleaning your firearms after occasional range sessions, and you’re not interested in reloading, then saving a few bucks with the power of aluminum is quite the appealing option. (Just make sure your range allows aluminum cases before your visit!) But if you’d rather trim as many minutes off of your cleaning time as possible – and have plenty of reloading components for later down the road – then nothing can replace brass.

What’s the difference between aluminum vs brass cased ammo? Aluminum cased rounds can be cheaper but what do you get up to save a little? We’ll help.