Debunking the Myth: Steel is NOT harder than Brass *(On your operating parts)

Conventional wisdom tells shooters that steel-cased ammunition is harder on a gun than brass. That is not the case. Bi-Metal and steel-jacketed bullets will wear a barrel faster, but steel-cases typically will not wear a bolt and chamber faster.

Now, Steel can be harder than brass (and it typically is). The steels used in bolts, barrels, etc are typically much harder than either steel or brass ammunition. The steels in steel-cased ammo is usually very soft.

YouTuber SaltyShellBack has the luxury of access to a Rockwell hardness testing meter and tested some off-the-shelf brass and steel ammunition.

Personally, my 3-gun teammates only shoot steel-cased and have plenty of rounds down the pipe with no issues.

Nathan S

One of TFB’s resident Jarheads, Nathan now works within the firearms industry. A consecutive Marine rifle and pistol expert, he enjoys local 3-gun, NFA, gunsmithing, MSR’s, & high-speed gear. Nathan has traveled to over 30 countries working with US DoD & foreign MoDs.

The above post is my opinion and does not reflect the views of any company or organization.


  • dp

    I believe this is not an issue (or perception for that matter) of “hardness” per se. You can have both ‘soft’ steel and relatively ‘hard’ brass. They will work equally well for ammo casing.
    It is perhaps issue of interaction – brass has due to its composition (shape of crystals/ microstructure) capability to ‘glide’ on smooth polished steel surface. Steel cases however are typically lacquered so unless you use it twice they should not create wear problem.
    Steel cased and coated ammo was developed by WP countries and as far as I remember no one questioned its capability or effect on long time wear.
    The wear on barrel is largely by erosion of hot gas ahead of chamber; nothing to do with material od case.

    • Dilby

      The cost of a new extractor is quickly outweighed by expensive brass cased ammunition.

      • On some guns sure, but on others they can be expensive and hard to find.

        • Arcane

          If you shoot crappy ammo out of a weapon whose parts are “hard to find,” then you’re an idiot. If a weapon has hard to find parts, then most likely it’s a relatively rare weapon and should be treated accordingly.

          • See the problem is with a ton of guns. For example, I have a few FNCs. If I break an extractor on fun mode, I am screwed. There are tons of guns with no parts out there.

          • Rusty Shackleford

            Alec C, will the FN FNC AK5 “Improved” extractor and plunger work for your rifle?

          • I dont know, but I would kill for an AK5 parts kit.

    • Frank

      You are right on, hardness is not the only factor. The other aspect you were describing is called the “lubricity” of the metal. Lubricity affects wear as well as heat generated from friction.

    • stealth916

      That lacquer is the very reason I don’t use it in most of my guns, save for the Saiga. That lacquer comes off and gums up the works. Steel is also more abrasive than brass. I will take self lubricating brass over lacquered steel every day.

  • Mike

    I don’t bother with steel cased anymore, getting a case stuck in the chamber soured me on it.

    • Pete Sheppard

      Yep. After several hundred trouble-free rounds, I had a steel stick in the chamber of my rifle; it had to be driven out with a rod and hammer. No more steel.

      • J.T.

        Who makes the rifle and is the barrel chrome lined?

        • Pete Sheppard

          It’s a Kel-Tec SU-16 with chromed barrel. The manual does discourage steel cased ammo, but I had not had problems in the past.

          • J.T.

            Ya. I wouldn’t trust their barrels to be 5.56 spec. I have talked to people that have had issues shooting brass cased ammo out of SU-16s. They are crappy, cheap guns.

          • Pete Sheppard

            Nah. They are good guns for their purpose, which is general sporting use, not hard combat. EVERY make of firearm has been claimed to be crappy and cheap. While I also want an AR, I am satisfied with the K-T, but steel ammo is now out.
            BTW, the range manager told me he has to beat steel cases out of rifles on a regular basis.

      • Mike

        Same, took quite a bit of effort to hammer it outta there.

    • Arcane

      More likely than not, that’s probably due to an out-of-spec chamber on the weapon. This is a notorious problem in the AR community with lower quality manufacturers (ie, Bushmaster, DPMS, Olympic, Stag, etc.), for example, who label their weapons as “5.56” when the chamber is only sufficient for .223. A Michiguns 5.56 chamber reamer will fix this problem:

      • Joshua

        The actual issue is that steel does not obturate the chamber like brass cases do. This allows more gas from the bore to bypass the case and get stuck between the chamber walls and the case, occasionally leading to stuck cases.

        It is especially noticeable if you fire a couple hundred rounds of steel, then toss in some brass.

        • Arcane

          That is an entirely separate issue from the problem discussed in my previous comment.

        • Steve_7

          Yep, absolutely.

      • Arcane

        I should also note that having a chamber out of spec combined with an oversized gas port is a recipe for disaster. Lower quality manufacturers are notorious for overgassing their guns, too.

      • Tim Pearce

        I’d honestly trust the gun manufacturer before the cheap-as-possible ammo manufacturers that typically produce steel cased ammo, when it comes to spec issues.

        • Arcane

          Obviously you do not know much about steel cased ammo, who manufactures it, and who uses it.

        • Geodkyt

          Um, THOSE COMPANIES listed above are known — through multiple independant verification — to have chambers that are not 5.56. Despite that fact that they invariably mark their barrels as being “5.56”. (Hell, that was one of the key facts that they used to hang Olafson by destroying his, “But they used incorrect “soft” ammo when they tested with .223 instead of milspec 5.56!” — his “5.56” marked barrel had a .223 chamber, because ALL of Olympic Arms rifles at that time had .223 chambers and 5.56 barrel marks. So, off teh shelf US made SAAMI .223 Remington *was* the correct ammo to test his rifle with. . . and it immediately went machinegun when tested with the correct ammo. . . )

          Worse, they are also known (for reasons of economy) to use their chamber reamers longer. . . which means that the last guns in line have a MUCH tighter chamber than the first ones. (Reamers make smaller holes as they wear.)

          The companies that make steel cased ammo have generally been making steel cased ammo since at least WWII. More experience making steel cased ammo to military specs than most AR companies have making rifles.

          That said, I avoid steel cased ammo in my ARs, NOT because of the extractor wear issues, but because they ALSO tend to use harder bullets that wear the rifling out twice as fast, while loading the rounds to lower velocities than US made milspec ammo. So, even though it would be cheaper (including twice as frequent barrel replacement) to shoot Wolf or the like, I stick to Federal and the like. (Yes, I *do* shoot enough that barrel replacement worries are justified. I can shoot on my property and buy my ammo by the case. Your average AR ownwer will NEVER shoot his barrel out, no matter what brand he shoots.)

      • dp

        And, in addition it is good to look at ammo too. If it is military surplus type (especially foreign), it can be made to looser spec (greater in mouth area). It might be worth to investigate Wolf steel ammo too, but what I heard so far it runs flawlessly.

      • J.T.

        When it comes to ARs at least, the pattern seems to be that steel cased ammo doesn’t run as well in guns that don’t have a chrome lined barrel.

  • strongarm

    Brass cases in steel chambers may also get advantage of “Statical Friction” on pistols like MAB P14 or Savage M 07 having rotating but not reciprocating barrels. Multi reloaded steel cases may not provide this.

  • Burst

    Another case of the comments being a bit more useful than the article itself.

    I wonder if steel casings would bind more in a revolver?

    • Geodkyt

      Well, I know from direct, personal experience, that aluminum cases are more likely to get stuck in a tight revolver chamber.

      Remember, steel doesn’t “flex” as well as brass — if it expands enough to get an equvalent seal, it likely won’t contract as far as brass would. So, if the chamber is a skosh tight, better chance of getting stuck.

  • ThomasD

    Hardness is not the only, and probably not the primary concern. Tribology being a rather complex science. The presence, or possible absence of various lubricants only serves to complicate more.

  • dan citizen

    Great article. I love this TFB trend to address current hot-button issues with facts and research.

    Rather then what most sites run….
    “Steel cases, will your rifle outlast one magazine?”
    “Brass cases, bourgeois status symbol, or antique danger?”

  • grego

    In response to this article, it depends on your goals what you should shoot….

    As to which is harder on your gun, that is a system question that can not be answered by looking at one variable.

    • CZFan

      yes it can, steel cases may be marginally harder than brass but they are still far softer than the bolt the carrier the extractor and the ejector, a softer metal or material cannot and will not abrade a harder one.

      Now bi metal projectile jackets are another story because of the heat and pressures involved a bi metal jacket will wear the lands of your barrel a little faster, than copper or brass, specifically the sharp corners. now the difference in barrel life for a gun shooting nothing but bi metal jackets and a gun using copper would be an interesting test.
      That being said I highly doubt that most people would ever know the difference, who really shoots out there barrels? competitors yeah, proffessionals maybe, they dont get unlimited ammo for training, so even that is doubtful, yeah an agency might shoot out a barrel in 20 years but not one person carrying or training with one gun would do it.

      Stuck cases are another story, If your gun is sticking cases and your extractor is repeatedly ripping the rim off cases that is obviosuly much harder on that particular part than normal cycling.

      • Cymond

        “a softer metal or material cannot and will not abrade a harder one”
        My grandmother’s sewing machine had a slit cut by countless miles of cotton thread.

        You are quite right that most people won’t ever shoot out a barrel, but it’s also not that hard to do, either. According to the Lucky Gunner Labs test, a barrel will be shot-out in less than 5,000 rounds of bi-metal jacketed bullets.

  • RickH

    Never had a problem or issue with steel cases. However I don’t like using a bi-metal bullet. Any manufacturers other than Hornady that use a regular bullet with steel case?

  • Frank

    Why do some people make little comments about countries like Russia or Serbia having poor quality or quality control?

    Have you seen the types of guns being put out by major US gin companies lately? It like a race to a plastic molded, MIM, cast, hell.

    Its not the 1970’s anymore. In many ways places like Russia, Serbia, etc are putting out better quality at a better price.

    Just saying…

    • Zachary marrs

      America makes much better gin.

      Just because the materials are different says bothing about quality.
      How is stamped sheet metal better than cast, or molded?

      • Frank

        Believe it or not, places such as Russia and Eastern Europe make a lot more than just stamped sheet metal guns, ala Kalashnikovs. Both Russian arms makers and Zastava in Serbia make sporting rifles, shotguns, and handguns. Many of these use materials such as forged and machined steel which are almost non-existent in modern produced American arms. You might also see a hard wood stock too. And..uh..yes, materials to say A LOT about quality.

        Don’t get me wrong, I am an American and immensely proud of the US firearms manufacturing history. We used to be on a whole different level than most of the world.

        Unfortunately, anyone with an engineering or manufacturing background realize most of the “progress” in US firearms manufacturing has been towards making things cheaper rather than better.

      • DiverEngrSL17K

        Good point, Zachary, but I have to agree with Frank. I would also add that it isn’t just a matter of whether the steel is stamped, forged, investment cast, machined from solid billet or whatever. It is also, more importantly, a matter of the actual quality of the steel material itself as it relates to the process and architectural design in which the part composed of said material was made. This goes beyond simply meeting set ASTM or similar equivalent standards, which are set up as minimal benchmarks to indicate that the material in question, at the very least, meets those standards.

      • Hopsaregood

        America makes better bourbon than gin.

    • n0truscotsman

      Im not sure, but its good for guys like me that buy Prvi Partizan ammunition, which is excellent.

  • MrSatyre

    I didn’t think that steel cases were harder on a gun’s innards than brass, but I had thought that not all steel cases expanded the same way as brass casings do, and that they were (slightly) more likely to not consistently eject properly.

  • raz-0

    It’s not the cases that concern most people, it’s the bullets.

    I’ll run hornady steel match stuff, and I did run the wolf stuff while it came with copper jacketed projectiles. I won’t shoot any ammo with copper washed steel jackets.

    If I’m going to mix steel and brass cased ammo in a rifle, I’ll perform maintenance at different intervals, and be picky about how soft the brass it. Both for reliability reasons rather than wear and tear.

  • DiverEngrSL17K

    It might surprise a lot of people that steel-cased ammunition rather than brass-cased ammunition is actually recommended by the manufacturer in certain cases, such as the Suomi 9mm M31 semi-automatic version of the KP31 SMG. In this case, brass casings are cited as having a tendency to swell in the chamber when fired, thereby preventing proper cycling.

    • Steve_7

      That sounds to me like that gun has been made with a tighter chamber especially for steel cases.

    • Geodkyt

      Likewise, most delayed blowback guns tend to do better with steel cases. . . especially when comparing steel cased to US civilian grade ammo (which has soft brass cases in comparison to even milspec brass cases).

      • DiverEngrSL17K

        Good point.

  • Steve_7

    But what is the definition of “mess up your gun” exactly? Back when surplus German and Czech 7.92×33 was around, people used to say don’t use it because it may be rusted. Isn’t it still the case that steel cases oxidize more easily? Also the argument I hear the most often is that steel-cased ammo doesn’t obturate as well as brass, so you’re more likely to have chamber cutting. I’ve seen that myself on a Mosin-Nagant. A Rockwell hardness test isn’t a test of malleability necessarily. Also steel and aluminum have less mass, so that can also cause problems as the springs tend to be calibrated for brass.