CAI M70B1: Gratuitous Full Auto

Yugoslavian AKs are very neat and stand out amongst their peers by having some very unique features. The gas cut off valve allows for rifle grenades to be fired (some folks modify this to reduce gas pressure when running a suppressor), they come equipped with night sighs, they have an RPK trunnion, thicker receiver, and I find their grips to be very comfy.

I was looking around for a good AK candidate to convert to full auto on a form 2 for some testing, and with its rigid receiver and trunnion I decided on the M70B1. You can find them online for just over $500 and thus I would not feel guilty making one into a post dealer sample using my SOT status to make the gun a sample for law enforcement sales. I loaded 15 magazines with Brown Bear steel 7.62×39 for a total of roughly 500 rounds (we loaded some loose ammo and shot it as well).

Converting an AKM to select fire is simple. I had a Yugo M70 parts kit and harvested the carrier, selector, and trigger group and drilled the necessary holes. You also have to cut out a section of the right guide rail so the trip lever has a place to rest. All in all it is much easier than an AR conversion, but it would be hard to do without the proper parts, jig, and drill press.

Anyways, in the name of scientific testing, this happened:



All in all I experienced two malfunctions. Both of which were probably a result of me messing with it (the bolt carrier failed to close all the way due to a burr preventing the trip lever from moving as freely as it should have).

So the gun worked really well all things considered. That said, shooting this gun made me reflect on this post.The only other fully automatic AK I have ever shot was a 5.56, which reminded me of shooting my FNC. The 7.62×39 was a whole different beast. I shoot machine guns all the time, including some in 7.62×51 but this AK was ludicrously hard to keep sighted on target. While the video does not convey this well, my friend and I both agreed that it was rowdy. The AK has earned a reputation as a gun that is easy to shoot, but I cannot imagine someone with no prior experience controlling this gun very well on fun-mode. The gun also got extremely hot very quickly, more so than any other assault rifle I have played with. Obviously steel is a good conductor of heat, but I have fired 300 round from an M16 with a 10″ barrel from 10 back to back mags and that gun did not feel as hot as this one.

However, since my friend CJ worked over some wood furniture I got from a parts kit, the heat has become less intense after trying it out several times. I think the gun turned out great! The writing on the stock says “Soviet” (I realize that Yugoslavia was technically non-aligned):





All in all, I am very impressed with this gun, and I hope you enjoyed the video!

Alex C.

Alex is a Senior Writer for The Firearm Blog and Director of TFBTV.


  • BryanS

    I love my yugo, but am always frustrated by the lack of mod fitment. Would love a forward charging handle for it.

    Man… $500. I bought mine for $250, and saw them as high as 2000 around here.

    • Y-man

      Try $10,000 for “reasonable” people in my country… [On the black market: maybe $5,000…] and ILLEGAL as hell!

      [Knowing you have one could lead to a Police ambush in which a you will be riddled with bullets when stepping outside to go to work!]

      Imagine: I got my Mossberg 500A for equivalent of $3,000!

      • BryanS

        Ouch. Yes, when it comes to owning arms, as screwed up as it is here, its always worse somewhere else.

  • Esh325

    Most Assault Rifles aren’t considered very effective for placing shots on targets anyways in fully automatic, even the M16.

    • I can do it but even for me, a very experienced person in shooting full auto, it is still quite difficult. Would anybody be interested in an article about the practical uses of full auto by exposing a machine gun virgin to it?

      • Ben M

        Yes. I volunteer?

        • You cmon down to Texas and you can be the trigger man.

          • Pigsnguns

            im in Texas!!!!

          • Shoot me an email.

          • big daddy

            Me too. I’m in Texas……..just got an AK, a little worried about the ammo not drying up and being hoarded. I had to change a few things, it was just hard for me to shoot, ergonomics. I have some issues with my hands and back so it was not comfortable. But it is a fun gun to shoot, I sure wish I could go FA.

      • Patrick Henry,The2nd

        Oh hell yea

      • Esh325

        And the only designs that I’ve seen that seem to address the lack of accuracy in burst or automatic are the AN-94,AK-107, and G11. The Russians spent a lot of time trying to improve the fully automatic performance of the AK as automatic was the primary mode of fire.

        • FN’s in 5.56 are very easy to control on full auto. The 7.62’s not so much.

          • st4

            How was the P90 when you used one?

          • HSR47

            The P90 is one of the odder MGs I’ve shot; On the whole I wasn’t particularly impressed with it. It isn’t the worst SMG I’ve ever shot, but it certainly isn’t the best either.

            In particular, I’m not really a fan of how the trigger works (on auto setting, short pull for semi, long pull for full).

            While it’s compact, and it has a massive magazine capacity, I tend to prefer guns that shoot something more than glorified super-high-pressure .22LR. The ammo is rather expensive, and it’s practical ballistic performance is rather weak.

      • Y-man

        I volunteer AGAIN! I am a good candidate for machine gun “re-virgination”! [Actually, I don’t really believe I have fired a REAL machine gun. Yes, on my last trip, and with your kindness, I got “Full auto-fire” introduction, but a proper machine gun? [Static braced position] Nope…

        • Ha, in a perfect world we would live on the same street Y Man! Always good to hear from you my friend.

      • Anon. E Maus

        Alex you knob, get a bakelite magazine for that thing and take some pictures for us, it would look excellent with the black polymer furniture.

  • Rich Guy

    That is a Century build kit gun. N-Paps (RPK receiver) and O-Paps (AKM receivers), are factory built Zastava Ak’s that are over all better quality,

    • Yep

      • HSR47

        You could always see about importing a factory gun, or buying one from an FFL not renewing their SOT….

    • M

      Century worked out a deal with Zastava so that they’d do as little modifications as possible to have a better weapon. They used to have to manually dremel and drill out the trunnion which was ಠ_ಠ.

      Now Zastava installs double stack trunnions/bolts and Century just uses a CNC machine to laser cut the sheet metal receiver to size. Results in a great AK for a low low price

      P.S. Even though they took out the human factor, I’m pretty sure someone out there will still say “I still dont trust Century with that”

  • John Sjöström

    When is people gonna get it the fact the main purpose of full auto is for suppress the opponent.

    • Or you’re about to be overrun.

    • Full auto has many applications. I once mowed down a field of hogs with a MAC 10:

      • hkryan


      • Y-man

        I need to get me some of this ACTION! Seems like 2015 may see more than one trip over there for me!

        • Ha, yes having you out with CJ and I would lead to a lot of fun and a lot of meat to cook up!

  • iksnilol

    Nice rifle and all but that stock is retarded. Relationship between Soviet and Yugoslavia was a bit chilly, or at the very least not so good that we would have their symbol on our rifles.

    Regarding muzzle control; try a suppressor + a recoil pad.

    • Arent you in Norway?

      • iksnilol

        In Norway, from Bosnia. I am most of my time in Norway except for a month or two vacation.

  • Patrick Mingle

    Out of curiosity under what circumstances would any LEO purchase a full auto AK?

    • Cymond

      I personally cannot imagine a LE dept buying an AK, but I’m not a LEO. There was one LE dept that hired Red Jacket to convert a Thomspon they had seized during a raid. Also, I can imagine a dept requesting a demonstration of an AK, just for the experience for their SWAT officers or whatever.

      • None I’m aware of. We had three Thompsons but traded them for credit to buy new MP5’s.

        • “We had three Thompsons…”
          Damn Phil, I bet those guns were as old, if not older than most of the folks on the job! One of these days we will convince you to write a book.

        • st4

          When I was still in OR, there was a transferable Colt 1928 at the shop I frequented that came from the Roseberg Sheriff’s Dept that looked as good as new. Hoo boy, I knew what I was gonna do if I had won the lottery!

    • k

      regardless of what many people think, individual officers do not have the ability to purchase NFA weapons without jumping through the same hoops as non-LEOs. NFA purchases are made at a department level, usually in bulk, usually SBRs or SMGs for specialized tactical teams. The only patrol officers you are likely to see with automatic weapons are officers in small or poor rural areas. These smaller agencies somtimes request federal assistance and obtain old military m14/m16s through the 1033 program for free, however they do not own the weapons and can not permanently modify or sell them, and must return them when they no longer want them.

      • Cymond

        I think he meant LE departments, not individual officers. He was calling in to question the probability of any LE department ever purchasing a gun that the general population identifies as a “bad guy gun” or “commie gun”.

  • Patriot Gunner

    “using my SOT status to make the gun a sample for law enforcement sales.” Riiiiight law enforcement sales *Wink* *Wink*. This is probably your SHTF rifle, and you’ve made a damn fine choice. No LE agency would ever even consider a combloc weapon let alone an AK because the AR platforms are more than reliable enough in an LE setting.

    • You would be surprised. Tiny departments with only a couple of officers have had AK’s especially back when they were so cheap. I have to say when I saw it well it just looked strange.

    • While I would not expect them to buy one, it is great to bring out to demos with PDs who can compare and contrast an AK with an AR15 or similar rifle to decide what they want to purchase. But like Phil said, smaller departments have a lot of flexibility in what they use. In a very small department, it could well come down to the individual officer’s preference.

  • doug

    very nice

  • Lance

    Be fun but for a none class 3 FFL a bit TOOOOOOOOOOOOOOOOOOO Expensive.

    • Cymond

      For a non class 3 FFL, it’s not expensive, it’s completely unattainable (legally). This is a post-86 Dealer Sample. It is not transferrable to private individuals at any price.

      • HSR47

        “class 3 FFL”

        “Class 3” refers to a type of Special Occupational Tax (SOT): Class 1 is for importers, Class 2 for manufacturers, and Class 3 for dealers.

        As he states at the beginning of the video, he is an 07/02 FFL, meaning that he has a type 07 FFL (manufacturer other than destructive devices) with class 2 SOT.

        • Cymond

          Fine, very well. The fact remains that it is not “TOOOOOOOOOOOOOOOOOOO Expensive” for “a none class 3 FFL “.
          It seemed that Lance was stating that it was expensive for anyone other than a Class 3 Dealer. It’s not expensive but it is only transferrable to those with an appropriate SOT. Transferrable machineguns and rare/unusual machineguns are valuable. This is neither.

          • HSR47

            My comment was simply meant to correct the terminology used;

            There are at present 9 types of Federal Firearms Licenses, and three classes of SOT. Class 1 SOT applies to importers, Class 2 SOT applies to manufacturers, and Class 3 SOT applies to dealers. Manufacturers and importers can also act as dealers without an additional FFL or SOT.

            Furthermore, as far as post-samples go, manufacturers have the easiest time by far: Manufactuerers can just build post-samples and then file the appropriate Form 2, whereas dealers need to obtain a request for demonstration from a government agency that can purchase post samples before they can apply to transfer a post-sample on a Form 3.

  • Alex, the Russian analysis of the AK concurs with your assessment. Several times it was judged “rowdier” than its competitors (e.g., TKB-517). This explains in large part, I feel, the continuing Russian obsession with recoil mitigation mechanisms (brakes, balanced actions, hyperburst).

  • gunslinger
  • supergun

    I saw a M16 fired automatically in boot camp. The sergeant rode around with it.