CASE METALLURGY: Do you shoot alternative-metal cases in your pistols?

HAVING JUST RECEIVED Magtech's new zinc-plated, steel-cased 9mm ammunition (magtechammunition.com), I was reminded that a lot of shooters don't understand the differences between brass-cased and alternatively metal-case ammunition. Or what they know may be wrong because there's a lot of misinformation being circulated.

In terms of pistol ammuni tion, there is loaded ammo sold with brass, steel, or aluminum cases. You can also find a few brands loading ammo with two-piece hybrid-case technology.

Though this is the "Handgunning" column, I feel a need to mention rifle cases. With rifle ammunition, True Velocity has made a name for itself developing polymer-cased ammunition. These reduce weight and resist heat better than metal, and the U.S. military is very interested in this technology's potential. In the 1980s and '90s, there were some efforts to develop caseless ammunition, as well, most famously in the HK G11 military rifle concept. Polymer guns, the 10mm cartridge, and caseless ammunition were considered cutting edge firearms tech back then, which is why "Aliens" Director James Cameron outfitted the "Colonial Marines" in the 1986 movie with the polymer-bodied M41A Pulse Rifle firing "standard 10mm caseless, explosive-tipped light armor piercing" ammunition. The 10mm is enjoying a resurgence, but nobody has been able to make caseless ammunition work properly in small arms, unfortunately.

There were cartridge cases long before there was smokeless powder, so don't think the cartridge case is a recent idea. The first metallic case was invented in 1808, which had a copper base and either a paper or brass case body. Encapsulated cartridges as we know them today didn't become the norm until much later in the 1800s.

Why did brass become the standard for cartridge cases? It was common and not too expensive. Brass tarnishes but it doesn't rust. Brass was stronger than copper and easier to work than steel. The metal in a cartridge case has to have some give and malleability, but not too much. It needs to expand upon firing to seal against the chamber wall in order to send as much of the expanding gas forward out the barrel. Brass stretches; it expands a bit as the cartridge fires, then returns to, more or less, its original size, which is why extraction isn't typically an issue. It's also slicker than other metals, helping it to slide more easily in and out of chambers. Brass was the best choice for cartridge cases for decades, and ammunition engineers figured out how thick to make the case walls to provide the necessary performance. Brass, just as importantly, has no "memory," which means it can be stretched and formed many times without weakening. If you couldn't, handloading with spent brass wouldn't be possible.

Why are there steel cases? A lot of reasons. During World War II, various metals were in high demand and short supply. Brass was considered a strategic metal, rarer and more expensive than steel. Almost every country involved in the war produced some ammunition with steel cases, and some countries never stopped.

Steel has its own issues, though. It is not elastic like brass. Instead of stretching, sometimes it splits. As a general rule, shooters don't reload spent steel cases.

Much of the steel-cased ammunition coming out of Europe and Russia is finished with a lacquer or polymer coating. This makes it a bit slicker, but the coating is mostly there to protect against rust, something you don't have to worry about with brass. There are stories about getting some rifles hot enough to melt the lacquer coating in the chamber, but I've seen AKs so hot the wooden handguards caught on fire without a functional issue feeding steel-cased ammo.

Most of the complaints about steel-cased ammo concern rifle use. For handgun cartridges, steel is a good alternative, though. Other than not being able to reload spent steel cases, steel ammo makes a lot of sense because it is less expensive than brass-cased ammo--sometimes significantly less expensive.

One worry a lot of people express about steel-case ammunition is that the harder steel will damage the chamber of their guns. Yes, steel is harder than brass, but it is softer than the steel of your gun. It's generally not pressed so tight to your chamber that it will cause damage during extraction. If it was that tight, the case wouldn't extract. Think about what's going on when you pull a trigger; the path of the bullet moving down the barrel is far more violent than the case entering and exiting the chamber. You'll shoot out your barrel before steel cases will damage the chamber.

Steel isn't as smooth as brass and doesn't shrink back once fired. If you have a rough or tight chamber, extraction might not be as smooth and you might get increased wear on your extractor. Again, this is mostly an issue with rifles, not pistols. Most people won't shoot enough to experience a difference--except in savings. Shooting steelcased ammo can save a lot of money.

The only real difference in performance you're likely to see is a dirtier gun. Some might attribute this to "lower quality" powder inside the less-expensive steel cases, but truthfully, it's happening because the steel case isn't expanding as much as brass and sealing the chamber; there is more blowback into the chamber and action. For the price savings using steel-cased ammunition, cleaning your gun more often is a great tradeoff.

The only issue I've experienced with differently metaled cases didn't involve steel cases, but rather aluminum. Aluminum is very light, softer than brass or steel, and less expensive than brass. Its softness almost makes it sticky, which can cause other concerns. I had a Glock consistently suffer extraction problems with aluminum-cased 9mm ammo. The case would get stuck in the chamber and the extractor would rip off the rim. It's not just me; split cases and case-head separations are more common with aluminum-cased ammunition. This means it is just fine for practice, but I wouldn't run it at a USPSA match where one jam means the difference between first place and the first loser. Not every pistol has a problem with aluminum-cased ammunition, though. I think it depends on the tightness of the chamber and the smoothness of the chamber walls.

In 2017, Shell Shock Technologies introduced its two-piece NAS3 (nickel-alloy stainless steel) case design. It paired a slick stainless-steel body attached to a separate base. With rifle cases, the base is stainless steel. With pistol cases the base is aluminum. The result was 50 percent lighter-than-brass cases while being stronger. It was advertised as being reloadable. As this is a proprietary design, I haven't seen a lot of ammunition loaded with these cases yet, and the ammo I have shot came from smaller manufacturers making specialty loads such as Fenix Ammunition's Match Grade series intended to make USPSA Power Factor (PF) requirements. Shell Shock can convincingly argue its NAS3 cases are superior to standard brass cases. I'm not convinced yet, but they are definitely more expensive!

Brass is still, arguably, the best material for cartridge cases. So, why buy anything else? In a handgun, you shouldn't expect to see any performance difference between using brass and steel, but there is a difference in price. Checking around; Magtech's new polished steel-cased 9mm ammunition was at least a dollar-perbox cheaper than the brand's identically loaded brass-cased ammunition. That savings can add up quickly, especially if you're shooting as much as you should be. E!

Caption: Though appearances vary, many cartridges utilize brass for the case. However, some manufacturers finish the brass with nickel coatings. While appearing similar to nickeled brass, some cartridges are loaded using aluminum or a hybrid stainless steel/brass for the case design.

BLACK OXIDE FINISHED BRASS CASE

STAINLESS STEEL RIM, NICKELED BRASS CASE

MATTE FINISHED ALUMINUM CASE

POLISHED NICKEL BRASS CASE

POLISHED BRASS CASE

Caption: Cartridge case development has prioritized alternative materials for rifle rounds to lessen weight and cost of production.

TRUE VELOCITY POLYMER CASE

POLYMER TRAINING ROUND. BRASS RIM

RUSSIAN STEEL CASE

CASELESS 5.7mm CARTRIDGE

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Title Annotation:	HANDGUNNING
Author:	Tarr, James
Publication:	Guns & Ammo
Date:	May 25, 2024
Words:	1334
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