JULY 20, 2026 – FORGET ABOUT M193! You no longer WANT its 55 grain full metal jacket (FMJ) projectiles. You’re taking the next step up in your pursuit of long-range precision. You’re stocking up on 5.56x45mm NATO M855 ammunition!
To be sure, M855 generally isn’t meticulously loaded and painstakingly standardized. It’s plain-Jane bulk 5.56x45mm target ammo – just like M193. It’s just loaded with a heavier 62 grain FMJ, which gains accordingly higher momentum once it takes flight. It exhibits superior downrange velocity retention, energy conservation, and wind resistance because of it, and follows the more predictable trajectory that simplifies long-range target shooting.
The M855 FMJ’s tip isn’t painted green solely to indicate that it’s heftier than the M193 alternative. Just beneath the jacket sits a 7 grain steel “penetrator” tip. This has three important ramifications for performance:
- Barrier Penetration – The M855 FMJ’s hard tip helps it pierce barriers more effectively. The penetrator can burst through 0.12” thick sheet metal at ranges out to ~665 yards under optimal conditions (although its likelihood of full penetration drops significantly at around half that range).
- Magnetic Attraction – The M855 FMJ’s steel component is ferromagnetic. Many gun ranges prohibit bullets that attract a magnet, as the steel they contain poses higher risks of (A) damaging range equipment, (B) emitting sparks on impact, and (C) ricocheting shrapnel back at the firing line.
- Steel Target Incompatibility – The M855 FMJ may not cut clean through an AR500 or other steel target. It will dent it, however, which you won’t be especially pleased about if you happen to be the owner of said target.
Is M855 Ammo Good for Home Defense?
M855 ammunition is assuredly effective at neutralizing a threat. The U.S. Armed Forces doesn’t issue it for combat because it’s otherwise.
Its enhanced penetrative characteristics aside, the M855 inflicts a pretty nasty wound channel. According to page 62 of this illustrative article, the M855 FMJ does the following when it strikes ordnance gelatin (which has approximately the same density as swine flesh) at a velocity of 3,035 fps (a muzzle velocity that is normal for a 20” barrel):
- Penetrates about 10”;
- Bursts apart into multiple fragments, excavating ~6” long permanent and temporary wound cavities in the process; and finally
- Continues penetrating to a depth of ~13”, at which point it retains half of its weight
Needless to say, the threat will not be amused if an M855 FMJ strikes them instead of ordnance gelatin.
That said, it’s hard to argue that M855 ammo is *ideal* for defense. It’s not loaded to the same higher standards for quality that ammo manufacturers generally reserve for their premium products. It’s also quite likely to pass clean through a human-sized target, at which point it can jeopardize innocent bystanders. Furthermore, a bullet designed to pierce steel also excels at piercing sheetrock – a barrier you should hope would stop your bullet before it can enter other rooms (including ones in your neighbor’s house.
My advice? Keep a healthy supply of M855 on hand for emergencies. You never know when a huge pile of military-grade AR-15 ammunition might come in handy. But if your AR-15 doubles as a home security system, consider keeping its magazine loaded with police-grade 5.56×45 (or 223 Remington) ammo like Federal Premium Tactical Tru or Speer Gold Dot. These rounds are manufactured in accordance with stricter quality control protocol, and armed with bullets which undergo true expansion to maximize trauma to the threat whilst reducing the risk of over-penetration.
What’s the Best M855 Ammo You Can Buy?
M855 is popular worldwide. It’s called “SS109” in Europe, and “F1” in Australia, but it’s all the same thing: 5.56×45 ammo loaded with 62 grain “penetrator” FMJs which usually (but don’t always) have green-painted tips.
Which M855 ammo is worth your hard-earned moolah? My own all-time favorites will give you a great start on your search.
Winchester USA M855 Ammo
- SKU – WM855K
Winchester manages the U.S. government’s largest small arms ammunition factory: the historic Lake City Army Ammunition Plant (LCAAP) of Independence, MO. If you reckon “The Big W” knows a thing or two about making the Armed Forces’ primary standard-issue 5.56×45 ball ammo, then you reckon correctly.
The M855 Winchester produces at LCAAP (headstamp: LC) is generally regarded as higher quality than that which they make in Oxford, MS (headstamp: WMA), but either would do your next range day justice.
PMC X-TAC 5.56 M855 Green Tips
- SKU – 5.56K
The nation of South Korea is one of America’s key allies. It makes sense that their military’s Daewoo K2 rifle accept the same STANAG magazines and 5.56×45 ammunition as our own Army’s M16 and M4. That way we can share vital supplies if our troops ever fight on the same front.
PMC is South Korea’s biggest ammo factory, and owned by one of the world’s largest nonferrous metal fabrication conglomerates. They exercise extreme control over their manufacturing processes, which yield all of the high-quality components PMC uses to make M855. (PMC calls it “LAP” for “Light Armor Piercing” although it is the same thing as M855 and compliant with the ATF’s ban on “armor piercing ammunition.”)
Federal Premium American Eagle
- XM855AF90
Federal Premium makes an enormous variety of rimfire and centerfire ammunition at their factory in Anoka, MN. This ammo is an exception. It was produced at LCAAP, making it more or less interchangeable with Winchester’s coveted LC headstamped ammunition. Pro? It’s packaged on ten-round stripper clips for faster reloading. Con? Federal Premium hasn’t produced ammo at LCAAP for some time now, which is why this fine M855 has become exceedingly hard to come by.
Igman
Igman was founded in Yugoslavia in 1950. They outlived their country of origin, and now export ammunition to over 50 countries from their headquarters in Bosnia and Herzegovina.
Virgin reloadable brass cases. Reliable noncorrosive Boxer primers. FMJs that can perforate 10 gauge (i.e. ~0.135” thick) mild steel at 1,870 yards. Reliable, and clean-igniting. Igman’s M855 checks all the same boxes as my American-made recommendations!
The Takeaway
Winchester is the preeminent domestic manufacturer of M855 ammo, and manages the U.S. government’s largest small arms ammo factory. Their USA series M855 ought to scratch any and all AR-related itches.
Federal Premium’s American Eagle label M855 is also great – if you can find it.
PMC and Igman both ship first-rate 5.56×45 ammo to the U.S. The foreign manufacturers may call it “LAP” or “SS109,” respectively, but it’s the same exact stuff we Americans call “M855.”