5.45X39MM Piston Gun

AR/M4 Beyond 5.56/.223
1

I had a user ask me for details on my 5.45X39mm AR-15 Piston Gun.

Here it is:

I wish the story of this rifle was sexy or romantic, it is actually pretty boring.

Last year while I was in Iraq I bought a full S&W M&P 5.45mm Upper from Bryan @ Aimsurplus.com. (Along with 4 “tuna cans” of 5.45mm (that is 4K rounds for the cost of less than $500.00 rounds of PMC or Centurion 5.56mm)

I had Jason Adams of Adams Arms send me a carbine piston conversion system.

I stripped the DI system off the upper, installed it on the 5.45mm upper and hooked up the DD Omega Rail and whatnot. Jason was particularly interested in this upgrade because this system was only designed to work with 5.56mm and the bullet weights and pressures generated by 5.56mm.

Well I can tell you with much certainty this gun runs like a freaking sewing machine. It has very low recoil, is super accurate (yes even with Communist Surplus Ammo) @ 300yrds, and the oooh/aaaah factor is high, especially at the range when you start loading magazines and people look at you like you are crazy.

The one thing that is a drawback is that Russian ammo is super-dirty, and even the piston system doesn’t keep the rifle totally clean, albeit it is way cleaner and cooler than a DI. The dirtiness actually just builds up in the chamber area. Other than that, you are GTG.

I have decked this beauty out with Larue/Magpul UDE Furniture, Arms #40L Buis, Troy Front BUIS, Trijicon ACOG TA01-NSN (with the JN3:16 in the SN), a POF AKS muzzle-brake (paying homage to the ancestry of the round, plus it is a cool brake) and topped it off with a helping of Surefire X300 on a Remote Tape.

I get these wild hairs and build rifles on a whim. This is one of them. And I am never letting it go, heck it can share ammo with his Tantal Cousin.

Semper Fi

BTW, I hate 16" barrels M4 profiled, they are retarded and gay… What can you do though. I am considering letting Randall over at ar15barrels.com cut my barrel down to an 11.5"

2

I have a 12" 5.45 barrel on order and was thinking about going the piston route.

Given the predominance of corrosive ammo, S&W should have hard-chromed the bolt and carrier IMHO. My DI 16" ran great in 1200 rounds at a 3-day VTAC class…all corrosive milsurp.

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PLEASE…who has 12" 5.45 barrels that can be ordered? Please state mfgr, twist if known and chrome lined? Price?

Thanks for any help,

openbolt

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Dude - this is awesome. Thanks for the redirect. I have an Ares GSG that I thought about, since 10.5-16" was not an issue with it in 5.56(gas wise), but it was redirected to a 5.56 MG setup of mine.

How are you in the cleaning dept, given you are shooting corrosive ammo - cleaning the piston system that is?

As far as Randall goes - i have some serious opinions on him - bunch of old TOS post about him and his inability to deliver. He did an ar10 barrel for me and it was great. Then I waited months for 5.56 work and ended up demanding a refund and still waited a while for return of an unfinished barrel. Lots of long phone calls in between. Maybe he is focused these days. He will no longer get any of my business.

5

Randall has taken on too much work it seems. It took 6 weeks for him to blind pin a FS. Maybe I will hold off on the barrel work…

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He has plenty of time these days to pontificate on Calguns.net.

I will hold off any further opinions of him.

You have some nive workhorses in your stable Motarman.

Although I was too woosie to get a 5.45 upper for my AR, I bought a Saiga 5.45 rifle instead. I especially like the fact that I can get 30 rounds for 4.00.

7

If you buy them for $129 for 1080, you get them for $3.58 for 30.

WWW.aimsurplus.com

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Current configuration