An interesting follow-up on my AR-15 ammunition post

Back in April, I wrote a three-part series about upgrading and outfitting rifles and carbines for personal defense.  The titles were:

  1. The personal defense rifle, part 1: a few thoughts
  2. The personal defense rifle, part 2: reader’s questions
  3. The personal defense rifle, part 3: choosing ammunition

In the third article, I recommended the Mk. 262 77-grain OTM round as an optimum selection for all-round defensive use.  It performs well at short, medium and long ranges, and is said to be preferred in 5.56x45mm ammunition by most US special forces units.  I use the Israeli version of that round, IMI’s Razor Core (reviewed at the link).

JC Dodge has just conducted his own test of the same ammunition, and reports as follows.

For a number of years I have been told by friends who have used the 77 grain stuff in combat, that it was a very effective round for the 5.56 AR platform. Although I have not talked to anyone who used a short barreled AR about its down range, real world effectiveness, I was curious, after I bought a a half case of it from

At almost 500 bucks with tax and shipping, that’s almost a dollar a shot, so I hoped I was getting my money’s worth. I was expecting good results out of my 16.5″ AR, but I did not expect my 11.5″ AR to exceed the longer barreled rifle’s performance.

. . .

I have shot plenty of AR’s which grouped well within two inches at 100 meters. I generally expect this kind of performance out of that platform in a quality build. Getting this kind of accuracy performance out of a short barreled AR, along with the numerous reports of the 77 grain OTM’s terminal performance on combatant “Target Interdictees”, makes selecting this ammo for a defensive weapon a “No Brainer” if you have an AR, and are able to get hold of some.

There’s more at the link, including some impressive groups on target.  The reader comments below the article, and user reviews at the SGAmmo link, are also worth reading.

It’s very hard to find this round at present, given the current shortage of defensive ammunition, but it’s worth keeping your eyes open for it, or any of the other versions of the Mk 262 from Black Hills and other suppliers.  It’s become my standard defensive load in my 5.56mm weapons.



  1. Hey Peter;

    Thanks for the recommendations. I have been using the 55 grain stuff because I have different AR platforms and the 55 will run through all of them and face it, 55 grain has been killing communist since the 1960's. I will look into the 77 grain bullets because I want something that will work and the 62 grain green tip can't run in my old school AR.

  2. Garabaldi, if you havea 1:12 twist barrel, it may not stabilize the longer rounds well. If so, look at Black Hole Weaponry barrels, direct or through surplus ammo dot com, (who sometimed has a sale with free upper and cheaper headspaced bolt and carrier), or the cold hammer forged CHF (FN) barrels from Palmetto State Armory.
    Good luck. John in Indy

  3. 1:7 is said by various well-respected ex-military people to be the best, at least in 16" barrels for stabilizing the heavier rounds. Obviously the faster you get those big projectiles spinning…I can't speak to the shorter-barreled ARs. Perhaps someone else can.

  4. I'm staying with the 55gr just because I bought tons of them super cheap.

    I'm broke enough to stick with loads of ammo I can afford to practice with.

  5. Like some others the bulk of what I have is M193. I will be keeping my eyes peeled for the 77 grain stuff though.

  6. AFAIK, military AR's have had the 1/7 twist since the late 80's. Only really old Vietnam vintage AR's have a slower rate, like the original Air Force purchases. 55gr seems to work okay in any rate from 1/12 to 1/7. Actually, 55 in 1/12 should work VERY well, judging by the early testing in VN.
    The reverse setup (HEAVY/SLOW) is very questionable.

  7. McChuck:
    yes, that is what made the 55gr/1 in 12" work so well. The problem was, according to the Army, that in very cold weather (Arctic), that the round had problems at long range. That is why they decided to spin it faster, which ruined the outstanding stopping power of the original setup. The Army has been chasing its tail ever since.

    Supposedly, at distance, the rounds would blow up when encountering Russian military winter clothing. So, they handicapped everyone just to be prepared for a potential Russian invasion of Alaska in the wintertime. Sheesh…

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