Thursday, January 31, 2013

My definitive 5.45x39mm AR15 article

I've been sitting on this article for some time.  Much thanks to Tam for prodding me into finishing and publishing it.  I will update this if folks have specific questions that I can answer. 

   In September of 2008, I bought a Smith and Wesson 5.45x39mm MP15R rifle.  This is a 16" barreled, M4 pattern AR15 rifle with a carbine length gas system, 5.45x39mm specific barrel, firing pin, extractor, bolt, and heavy hammer spring.  The heavy hammer spring is needed to ignite the Soviet/Russian ammunition that has hard primers.  The heavy hammer spring gives a roughly 7-8lb trigger pull with a positive reset.  This may concern those that are used to light triggers; positive reports abound of the Geissele triggers being able to handle the hard primers, some with the heavy duty hammer spring, some without.  Myself, I bought this carbine to primarily save money and I am a fan of triggers heavier than the American gun owning public likes so I adapted easily to the "heavy trigger" and don't see the logic of installing a $300 Geissele trigger in a "training" rifle.  The only part you need to change out on a standard AR15 lower in order to use this 5.45x39mm upper is the heavy hammer spring.  The weapon shipped with a black extractor spring insert and a 5 coil extractor spring.

  I have roughly 25,000 rounds of Soviet surplus 5.45mm ammo through this weapon.  The first barrel was shot out at roughly 12,000 rounds.  It went quick.  As in I was shooting fine and the next thing I knew, the rounds were hitting the target sideways or what is commonly referred to as "keyholing."   I called S&W, they issued a call tag on their dime, I had the rifle back with a brand new barrel in six days.  They paid shipping for the return as well.  Included was a terse note reading "bad barrel, replaced."  At around 15,000 rounds the weapon started going full auto at the range and was immediately shelved.  Once again, S&W fixed the rifle on their dime in less than a week.  This time the entire fire control group (FCG) in the lower was replaced.  A note on key holing bullet strikes; it is not uncommon to see this here and there using the Soviet surplus ammo.  That is mainly an ammo problem.   If you're seeing some key holing, test different ammo lots and brands.  If it continues, you probably have a shot out barrel.

50 yard target showing the effects of a shot out barrel

 The primary draw of the 5.45x39mm cartridge to American shooters is that it's a cheap substitute for the American military issue 5.56x45 and civilian .223 rounds (not identical!).  Felt recoil is a little less than that of the 5.56.  Aside from the heavy hammer spring, bolt, magazines, barrel, and firing pin; everything else on this weapon is identical to a similarly configured 5.56mm AR15.  The max point blank and holdovers are very similar to the 5.56mm; certainly close enough to use as a 5.56mm AR training analogue without busting out a ballistics calculator.  Soviet surplus 5.45x39mm ammunition is still amazingly cheap if you can find in during the Barackolypse 2.0.  At the time of this article (01/31/13), I ordered 2160 rounds delivered to my door for the whopping sum of $339The very next day, PMC 55grain .223 training ammo is going for (it will sell out before lunch) $12 per box of 20.   108 (2160 rounds) twenty round boxes of .223 at $12 per box is $1296.  $1296 minus 339 equals 957 dollars saved by going with the 5.45x39mm AR.

  There is precisely one choice for quality defensive/hunting ammunition and it's the Hornady V-Max ammo.  I have some; I have not tested it during hunting nor any form of ballistics testing.  There's some encouraging results from the field here

  That brings us to the cheap ammo.  You can either use dirt cheap (roughly one 1/3 the cost of brass 5.56mm) Soviet surplus ammo or factory new, Wolf steel cased ammo.  Obviously, if the cheap stuff works, this setup can save you some money.  Good news: it does.  I've attended the below carbine classes using this carbine and never once fell behind because of accuracy or reliability issues. If I do my part, it will shoot like this ALL day long.  (required joke)

10 shot group at 100 yards (plus a few more for good measure) group from prone using a 4 MOA red dot and Soviet surplus ammo manufactured in the 70's shot at Kyle Defoor's 2 day Advanced Carbine class. 

  Using good magazines and a properly setup carbine (good springs and lube), this rifle is as reliable as any Glock I've ever owned.  I did mention "good magazines."  The best magazines I've used are purpose built for the 5.45 AR, C-Products and ASC magazines.  The ASC magazines are supposedly built by the company that bought out C-Products according to errornet RUMINT.  I've had good luck with both C-Products and ASC mags except for four of the below from C-Products.  Note the top (in the picture) feed lip.  I would love to exchange these for in spec magazine bodies.....

  I've had some luck using downloaded Gen1 Lancer magazines and Magpul EMAGs.  If you're going to try using non 5.45 specific magazines, start off with the magazine downloaded to 20 rounds and watch for the magazine's feed lips to spread.  Really, this weapon's biggest failing is that of all magazine fed weapons:  the magazine.  Try to scrounge up some 5.45 mags if you can.

  I have never messed around with modifying 5.56 magazines to work properly but....this article from Surburban's Domain is so well done, there is no need in me bothering to put up an article should I decide to hack on some 5.56 mags.

  On to religion.....  I speak of course of that faith American gun owners follow in that the act of worship (cleaning way more often than needed) will persuade your weapon god to reward you with good service.  Normally, I'd clean an AR15 every 1500-2000 rounds whether it needed or not and then my cleaning ritual routine would be blast out the weapon with non chlorinated brake cleaner (outdoors of course), push 2-4 patches of carbon and then of copper solvent, and then relube generously with whatever's on hand.  However, the corrosive salts used in the ammunition of the popular Soviet surplus 5.45mm ammo means that I actually have to do more.

Cleaning when using corrosive ammo

  I've tried several different cleaning routines over the years and have settled on the below after every time I fired the weapon.  It works and has for roughly the last 10,000 rounds I've put through the weapon.

  1. Rinse the field stripped weapon with water (preferably hot but it doesn't really matter so long as you flush it copiously), all over , and sparing no area.  That means as a minimum, breaking down the bolt carrier group (BCG) and rinsing each part (copiously) in the BCG individually along with the barrel, chamber, and gas tube.
  2. Shake/air dry.  Add a little lube.Push 2-4 carbon solvent soaked patches on a jag if you've just fired over 200 rounds (optional).
  3.  Reassemble, function test.
  Every few thousand rounds or so, I'll add a thorough hosing out with non chlorinated brake cleaner after the water rinse.  

  The corrosive stuff in this ammo is a salt.  Salt does not dissolve in oil.  Salt dissolves in water.  Salt dissolves more betta' in hot water.  

  Trust me folks, I've tried the Windex route.  It just adds complication and I'm a simple man.  I've done the plain water rinse for literally thousands of rounds and it works.  I've tried adding more lube instead of cleaning (didn't work) and cleaning only with non chlorinated brake cleaner (didn't work).  You must clean this with a rinse after shooting corrosive ammo.  Windex will work, water is cheaper.

  You can go longer without cleaning in more arid environments but even a quick dunk in a lake/stream will work in the field.  Here's what you can expect to see if you prolong a water rinse after shooting.  A fresh water rinse, a light scrubbing with WeaponShield and the parts were back in business.  I do not advocate mechanical removal (that is scraping) of carbon.  I have never scraped carbon off of this rifle's internals and never will.


  The weapon was upgraded upon advice of folks I trust in gun forums with an "O-ring" extractor upgrade and the carbine weight buffer to an "H" buffer.  This was when the weapon was new.  At around 15k rounds, I knew I was going to need a spare bolt so I bought a bolt and firing pin from THE 5.45x39mm AR people; US Armory Corps.  It was a pleasure doing business with them, highly recommended.  I have never needed the spare bolt but it resides with the spare firing pin inside of my Magpul MOE Plus Grip (the rubberized grip is comfortable and very grippy).  I also impulse bought a nickel boron coated Kiess BCG (Bolt Carrier Group) and swapped it out.  I have no problems with the Kiess BCG but do note that it's certainly not immune to the surplus ammo's corrosive salts.  That being said, it cleans up far more easily when blasted with non chlorinated brake cleaner and does seem to have a more resilient finish.  Time will tell.

  I am happy to note despite boohooing and hand wringing over the effects of steel cased ammo on extractors, I'm still using my original.

  All springs and the gas rings are replaced at or near the recommended AR15 intervals.

  A careful observer will note that I use a captured firing pin retaining pin.  I've lost two during my outdoors cleaning of this weapon and this piece solved that problem.

  Below pics of the weapon as currently configured and its internals after over 24,000 rounds of corrosive Soviet surplus.

Before cleaning

  After water and non chlorinated brake cleaner cleaning:

Cleaned, lubed with Slip2000 and ready to go.

Back together.  The weapon is wearing a Troy 13" TRX Extreme rail/handguard, front Magpul MBUS sight, YHM rear sight, Magpul MOE stock, Magpul MOE + grip, Vickers padded sling,  Aimpoint Micro H1 red dot sight (RDS), and a Surefire X200 light.  It does not match cosmetically and at least 3 of the parts on the weapon are there because friends didn't want said parts.  Nevertheless, I would trust my life to this well worn weapon and am quite happy with it as configured.  The savings in ammunition costs are readily realized with this weapon if you properly maintain it and do not plan upon reloading spent cases.


  1. " least 3 of the parts on the weapon are there because friends didn't want said parts."

    Hey, a lot of loyal dogs have come from the pound. ;)

  2. I've heard some horror stories about the S&W 5.45 barrels keyholing as early as 5,000 rounds. I take it you haven't had the same issues?

    I just recently bought this rifle in January and have only shot the Russian surplus stuff so far but wanted to make sure that type of ammo is good to go.


  3. kevinlin, if you read the article again, you'll see that my barrel burned out at 11k rounds and S&W replaced it for free on their dime.

  4. I saw your comment

    "I do not advocate mechanical removal (that is scraping) of carbon. I have never scraped carbon off of this rifle's internals and never will."

    Can you explain this a little more in as it pertains to all weapons not just necessarily a 5.45 upper. I'm just pretty curious as to the theory/reason behind your recommendation.

  5. Mark, if you're scraping with metal on metal, you're altering precision fit pieces. Better to soak with solvent and brush off, starting with an AP brush and then maybe moving to a wire brush if you MUST but honestly, people really, really overdo cleaning of guns.