Throwback Thursday—Shooting Steel Cased Ammo In Your AR-15

By CTD Blogger published on in Ammunition

You have no doubt noticed the large amount of inexpensive steel-cased ammunition available. It is hard to pass it up—prices for steel-cased ammo are cheaper than that of traditional brass-cased. Take it out to the range and it won’t be long before you hear the “tsk-tsk” of other shooters, commenting on how horrible it is to run steel-cased ammunition in an AR-15 style rifle.

But is steel-cased ammo really so bad? Is it safe to shoot steel-cased ammunition in your AR-15?

Busting Myths

Picture shows a steel-cased .223 Remington round.

Steel cased ammo may have gotten a bad rap, but there’s nothing wrong with it.

Let’s own up to a few facts first. In general, discount steel-cased ammo is dirtier and smellier than MIL-SPEC Lake City manufactured 5.56 NATO ammunition. Further, it is not quite as accurate either, but many shooters won’t miss a half-MOA here or there.

Now, on to some myth busting. Modern production steel-cased ammo is not corrosive, even when Berdan primed and it will not destroy your extractor. The ferrous bi-metal jackets found on most steel-cased ammo will not damage the rifling of your AR and are perfectly safe to use on any rifle-rated backstop.

Dripping Wet

What do you need to do to run steel-cased ammunition in your AR-15 successfully? First, you will need to make sure your AR-15 is well lubricated. Dripping wet some might say—especially the bolt carrier group. You will need to clean your rifle more often when shooting steel-cased ammo; at least once every 500 rounds. However, you could get away with letting it go for up to 1,000 rounds. Because steel-cased ammunition results in more carbon build up, it’s important to use a high-quality solvent like M-Pro 7 along with a synthetic lubricant. Thoroughly clean your bolt, paying close attention to the bolt face and extractor. It is usually a good idea to remove the extractor to clean underneath as well. You will also need to clean the chamber with a good M16/AR-15 chamber brush.

Modern Coatings

Steel-cased ammo is generally loaded lighter than standard military loads, so it is important that the AR’s gas system runs well. Some AR rifles have smaller gas ports and will not cycle well with the reduced-power loads found in steel-cased ammunition. If this becomes a problem, switch to brass-cased ammo such as PPU. Using a lower-weight buffer or a lighter buffer spring may also be necessary when shooting steel-cased ammo.

Steel-cased ammunition is available with three different types of coatings. To help prevent rust and corrosion of the cartridge case, older steel-cased ammo is lacquer finished. Brown Bear still uses this coating. As heat begins to build, some AR-15 rifles start to have problems with lacquer-coated, steel-cased ammo. Switching to modern production steel-cased ammo with polymer coatings sometimes alleviates this problem. In other cases, it may be necessary to use zinc-coated steel cased ammo such as Silver Bear.

5.56mm v .223 Remington

The best way to avoid extraction problems due to stuck cases is to use an AR-15 with a 5.56mm chamber. Differences in headspacing between 5.56 and .223 chambers can cause steel-cased .223 or 5.56mm ammo to get stuck as the metal heats up. Even Wylde chambers and other .223/5.56-hybrid chambers have issues with stuck spent steel casings. Stick with a true 5.56mm chamber and, as mentioned, remember to scrub the chamber out every 500 to 1000 rounds to ensure reliability.

Steel-cased ammo may have gotten a bad rap, but there is really nothing wrong with it—so go for it! Some AR snobs may sneer at the mere thought of running steel-cased ammo through their precious rifles, but you know better now. Save money when plinking and try out steel-cased. Most AR-15 rifles run it just fine with no problems at all.

Do you run steel-cased ammunition in your AR-15? What have you found that works best? Share your tips and tricks with others in the comment section.

This article originally published on May 27, 2010.

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Comments (117)

  • Christian


    From what I read in the “Steel vs. Brass Epic Torture test” on last year it seems more of a barrel issue. From their test the steel cased ammo wears out your barrel a quicker. This is because the rounds have metal in them. If you put a magnet to a lot of the steel cased rounds[bullets] it will stick. This means the FMJ and/or interior has metal in it. Through repeated use it appears that this wears out the barrel quicker. This is the bigger issue for me personally; not whether it feeds well or is dirty…


  • Deryl


    I have been using Brown Bear steel cased, fmj ammo in my 7.62 x 39 AR15 for years. I have had zero operational issues…none. As an added bonus, the 123 grain Brown Bear runs very consistent and accurately in my particular weapon….better than many, more expensive rounds…


  • John


    You state “Using a lower-weight buffer or a lighter buffer spring may also be necessary when shooting steel-cased ammo.” but never explained why this would help. I was always under the impression that it had to be opposite – heavier buffer with stiffer buffer spring to slow down the cycle rate that will improve the FTE problems.


    • Secundius


      @ John.

      When the inside barrel “heats-up”, temperature is transmitted back in to the “steel” cartridge and causes it to expand. As the barrel “cools-down”, allowing the barrel to contract. The steel cartridge stay hot, essentially “welding” itself to the inside of the barrel.

      There is another method you may or may not want to try, is getting a “paintball quick charge” device. Place it at the end of the barrel, release the small co2 cartridge. And use the co2 pressure blast, “ballistically” blow out the spent cartridge. Barrels vary, and this does not, unfortunately work with all pistols and/or rifles.


    • Aaron


      The first sentence of that paragraph explained it, “Steel-cased ammo is generally loaded lighter than standard military loads”

      You want a certain balance in the cycling of your rifle. Lighter ammo needs a lighter buffer and spring to be able to fully extract and eject. Heavier loads need a heavier buffer and spring to absorb that energy. This is all before getting into gas port length issues.


  • ray3toes


    Got my S&W M&P sport about 5 months ago, have run Wolf 223 and 556 for most of the 1,000 or so rounds. Did try some Fiocchi, 10 mags full and had one round hang for some reason. My S&W seems happy with most anything i feed it. Try the steel before you knock it.


  • RegT


    Since switching to the polymer coated steel case ammo in .223 and 7.62×39, I have had zero issues with any of my rifles. No issues with carbon either, since my Bushmaster M4gery has had an Adams Arms gas piston kit installed (love it). Both it and my 1946 Russian SKS operate flawlessly.

    The cheap Tula/Wolf steel case ammo is great for practice, with Lake City used in the M4 when loaded for “duty”.


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