Multi-Caliber Capable AR Magazine

DIY designer Jing Zheng has submitted a few videos to YouTube of his multi-caliber capable AR type magazine design. He first announced it to the public in December 2011, as the Longziz #2, it is capable with 6.5 Grendel, 6.8 SPC, 5.45x39mm, 7.62x39mm, and the STANAG mag. staple .223/5.56mm. He is currently looking at testing with the .300 BLK.

In this video he loads five rounds from each caliber into one single magazine, he fires four rounds, removes the magazine, fires the last round of that caliber and moves on to the next caliber carbine.

Some buzz has been around since 2011, the following was a post he made to when he first announced it.

“The idea is very simple. The M43 round will introduce far more tilt inside of the STANAG magazine comparing to other calibers. If a non-tilt follower is used, the rounds can have a nose dive if certain amount (very small) of ammo is inserted, hence more prone to induce jam. If a tilt-able follower is used, the follower tend to tilt too much if a large amount of ammo is inserted, such that the follower would slide into the gap between the round tips and the front magazine wall and cause the ammo tail sink into the cavity the follower left behind, which also introduce jam. So I thought, maybe I can use a two piece follower approach, one that is non tilt, while the other is tilt-able. This way, the follower assembly would be stable inside of the magazine, while the tilt-able piece to accommodate tilt introduced by the ammo.”

Jing is no stranger to rethinking existing designs, the Longziz #1 is a bullpup rifle he developed over several years, which utilizes AR15 lower receivers.

The following test is loading the same magazine entirely with one caliber and quickly unloading the weapon down range. The video isn’t as interesting but I appreciate he does not edit or retake the video and instead shows the few failures with 5.45x39mm and 7.62x39mm.

Though some are worded as an estimate, the magazine capacity is as follows.

  • 23/24* rounds of 6.5 Grendel
  • 25 rounds of 6.8 SPC
  • 28 rounds of 5.45x39mm
  • 24/25* rounds of 7.62x39mm
  • 30 rounds of .223/5.56mm

* The extra round will fit but will not insert easily on a closed bolt.

The initial magazine release will be of steel construction. There is no price or date on production, it is simply too soon to tell, but he assures repliers he is working towards this goal. Considering the cost of purchasing several types of magazines and the price of the higher quality special caliber mags – what would our readers pay for this kind of magazine?

Ethan M

Ethan’s firearm interests are mostly with Cold War era select-fire weapons and their semi-auto counterparts.


  • zem

    I knew he looked familiar, honestly im more interested in how his longsiz is coming along, but in reference to his magazine i dont know if i would purchase one of those because i seperate all my ar’s magazine by brand and caliber and mark them accordingly so i dont mistakenly put a .300 blk magazine in a 5.56 gun and vice versa but his designs may lead to higher capacity/reliability design so keep up the good work!

    • Jeff

      Nothing bad would happen if you did. In fact parts interchangeablity is touted as being a strength of 300.

      • zem

        No duh they use the same magazine what i was trying to say is i have dedicated magazines so i dont put a magazine full of 556 in th 300blk chambered gun and vice versa. Reading comprehension ftl

    • KeithF

      Considering the fact the 300BLK was designed as 100% compatible, to include capacity, with 5.56 mags (by using 5.56 brass as the base) this comment makes no sense from someone who has shot 300BLK or to someone who shoots 300BLK.

      In fact there are no such 300BLK magazines, not like the ASC or CProducts 7.62×39 or 6.5 grendel mags (the former being a different shape and the latter built with blue followers for distinguishing between it and a standard mag)

    • -V-

      .300blk already uses standard 5.56 mags, so what’s your point? One of the main strengths of his design is now the same magazine can be used to feed multiple caliber uppers, so any need for a 6.5-specific or 6.8-specific or 7.6×39 specific magazine is removed.

  • rjackparis

    If it feeds well he could effectively put quite a few magazine makers in a tough spot. But then again, .40 glock mags will feed 9mm according to certain NY gun stores. ( I’ll leave the implications to you) but people still buy dedicated 9mm mags.

    • smith934

      Don’t know about the Glock Mag but i can tell you that Beretta 40 mags will feed 9mm, but the bullet tends to ‘rattle’ down the bore…

  • Major Nav

    How long to the first personal injury lawsuit for the wrong caliber fed into the wrong gun?

    • -V-

      With the different dimensions of the various ammo, you’ll get a jam if you try to feed x39 in a x45 or a 6.5 in a 6.8 or vice versa. Dimensions are simply too different.

      • noob

        behold! if the bullet has a bad crimp, you can chamber a 300 blk in a 5.56mm gun because of excessive bullet setback. This will probably cause a kaboom due to a bullet shaped bore obstruction. This will of course happen with a standard GI magazine too.

        If you try to put a 5.56 into a 300 blk chamber the bolt will not go into battery by design.

        It may be interesting to test all the possible calibers in the longziz2 multi caliber magazine using empty cases.

        • JSK

          So what you’re presupposing is that you first manage to get a round of 300 blk that is set back enough to feed into a 223/556 chamber (probability is so damn low) and then also manage to not notice this anomaly when loading the magazines and also loading the wrong ammo type into the wrong firearm.

          • noob

            if you behold the video, the failure mode is a reload 300 blk with *no* crimp on the neck, allowing the bullet to set back after the round is chambered.

            The realistic scenario is this:

            say a handloader is unfamiliar with 300 blk and makes a batch of 300blk with weak crimps holding the bullets. These cartridges are loaded into a GI mag and forgotten about.

            This handloader is also careless and doesn’t put a big 3 on the side of their magazines that are dedicated to blk, or maybe they don’t dedicate magazines.

            The mag full of 300blk with the dodgy crimps is inserted into a normal 5.56mm AR15.

            The bolt closes, chambering the round (as seen in the video) and pushing the bullet into the neck of the case as it slams into the neck of the 5.56mm chamber.

            What happens next is entirely the fault of the this dangerously careless hypothetical shooter, but apparently has happened more than once.

            You are right that it could be avoided by paying attention and using a sharpie to mark dedicated 300 blk magazines.

            to tie it back to topic – do we need to get a disclaimer on multicaliber magazines to protect Longziz from lawsuits when the inevitable kabooms occur due to user error? I believe the answer is yes. There is always somebody out there who will do things that will blow their own faces off with your product, no matter what you do to make it safe.

  • PAT

    yo magpul go hire this guy

  • Max

    Test it with .50 Beowulf and/or .458 SOCOM. If it works with those, label it a 10-round .50/.458 magazine.

    Then sell it in jurisdictions that limit ammo capacities.

    • SP mclaughlin


    • Tom – UK

      great idea!

    • Komrad

      They already do this in Canada. They have 5 round mag caps, but it’s based on what it says on the mag. They use 5 round .50 Beowulf mags with 5.56 adnget 15 round mags legally.

  • Iblis

    Could go for a 30 round 6.8 SPC mag, but like others have said, magpul should buy this guy’s idea and run with it.

  • John184

    How’s the reliability?

  • Nathaniel

    This is a not-so-great idea from a practical standpoint. Firstly, it offers little or no attraction for most militaries, as they will typically use only one of those (in the big scheme of things) very similar rounds.

    Secondly, users of multiple calibers will want to keep their ammunition segregated (and in different magazines) to avoid a dangerous ammunition mixup.

    Thirdly, it would be problematic to make the magazines reliable for all the types of ammunition; any magazine purpose-designed for the ammunition you’re firing is highly likely to be more reliable.

    Fourthly, it adds complication and cost where none is needed (Will this magazine undercut the prices of 6.8 SPC, 6.5 Grendel, 7.62×39, 5.45, or 5.56 AR mags? If so, why couldn’t a conventional mag be made as or more cheaply?).


    It’s quite an excellent publicity and engineering stunt, as it’s simple, impressive, and not worth copying (Mr. Zheng is clearly very clever, and isn’t telling us about all his marketable ideas). I wish him the best of luck.

    • noob

      As it has been said above, the main exciting thing about this magazine is the innovative two part follower that means you can put a tapered case into a straight magazine.

      you might even be able to make a magazine with an extreme dogleg curve in it (near 80 or 90 degrees) so the bullets feed horizontally along the handguard and then turn around a gentle radius and go up to the feed lips. That would give you a large capacity magazine without resorting to more complicated helical mags or drum mags.

  • Arca

    He should put it on Kickstarter and post links to it on and

  • xerodown

    if it shot 5.45 reliably it would be worth its weight in gold!

  • Rick

    this guy should be celebrated to help break the hoplophobic perception that only white guys are gun nuts. 🙂

    His designs bust paradigm so badly that even I gotta stop and think about them.

    freedom and arms come from everyone, all peoples, all walks of life. We may have the next Browning, Stoner, or Kalashnikov here.

  • Carl

    Maybe We can finally have Straight 7.62×39 AK Mags…

  • Longziz

    Thanks Ethan for your article! And thanks for some very good comment I have read here. I will take some of them into consideration for the production version.

    Please allow me to make some clarification here as well. The mag is not intended to replace any market existing mags, let along to be adopted by the military. Rather, it is to served the need for what is lacking in the current market. 6.5, 6.8, 5.45 and 7.62X39 to be specific. And just in case you want to use it to feed your 5.56, it is possible. So far it is just a prototype, so I will let you guys to judge the reliability of it when it is available.

    As of putting wrong caliber into the wrong rifle, first, the mismatch caliber in one mag is just served to show the fact that the mag is not picking on the caliber or cartridge casing. The reason I did it is no other than show-off or spicing up people’s interest. There are un-intended consequences if it is wrongfully done or just been careless or even stupid. Maybe I should have people sign up a disclaimer before they buy?

    The current GI style mag are capable for 223 and 300blk. I haven’t seen anyone not buying GI mag for 300blk simply because it might be mixed up with their 223. The key is to clearly mark them and separate them in storage. I don’t see any point why the same technique can not be used with this mag.

    Anyway, thanks for your comment and please keep it coming so I know any draw back this mag might have, so I can address it accordingly before I put them into the market.

  • Avesta Dayeny

    This is quite possibly one of the best ideas I have ever seen for this particular weapons platform. This is an absolute godsend for weapons like the Tavor SAR and Beretta ARX160, that can only take STANAG type magazines but have multi-caliber support via interchangable barrel systems. If you start mass-producing these I will be the first to buy at least 50 of them…lol amazing and innovative design!