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?
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.
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.
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.