“Can We Keep Him?” – The 6.5×39 Grendelski

Title Image: Wolf Performance Amunition makes steel cased 6.5 Grendel; most likely the inspiration for the new round.

A stray has followed them home: Russian small arms designers have apparently created a close clone of the 6.5 Grendel, called 6.5x39mm. At first glance, I thought this CIP specification from 2013 was just that of the 6.5 Grendel, submitted as part of Wolf Ammunition’s work with Alexander Arms to create steel cased ammunition in that caliber. However, if one looks closely, it is clearly different: The case is slightly longer than the 6.5 Grendel (by about .015″), and the cartridge retains the case taper of the 7.62×39  (about 1.3 degrees, whereas the Grendel has case taper about a third of that).

Given the different dimensions, we can expect this round to be 50-100 ft/s slower than the 6.5 Grendel, but otherwise similar. It’s likely the case taper was chosen to give the round compatibility with existing 7.62×39 magazines.

It’s possible that this – and not the 6.5 Grendel – is the “other intermediate cartridge” reportedly involved in current Russian small arms development. It’s also possible that this is a test article only, in fact, and that the round the Russian developers are eyeing is in fact the unmodified 6.5 Grendel. Whichever is the case, this is yet another hint that Russian small arms designers may have gotten “a little bit pregnant” with the 6.5mm intermediate round concept. I would be most interested to see the results of a “shoot off” between 5.45 and 6.5mm AK-12s, should that ever happen.

Thanks to Daniel and Alex for the tips.

Nathaniel F

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. In addition to contributing to The Firearm Blog, he runs 196,800 Revolutions Per Minute, a blog devoted to modern small arms design and theory. He is also the author of the original web serial Heartblood, which is being updated and edited regularly. He can be reached via email at nathaniel.f@staff.thefirearmblog.com.


  • erwos

    Obvious question: can you safely fire this from a Grendel chamber? I’d definitely be game for an AR in something like this if the Russians decided they wanted to export cheap steel-cased ammo.

    • Ethan

      Yeah, 6.5 Grendel Ammo for <$6 a box would definitely get me on board.

      • ClintTorres

        How about $7 a box? See the link above.

    • ClintTorres
      • erwos

        36c/round? Wow, that’s pretty good. Probably even cheaper once the exclusives deal expires. Might be time to buy that 6.5 Grendel upper!

        • ClintTorres

          FYI – If you plan on shooting steel-cased, it is recommended that you get a chrome-lined or nitrided (aka Melonited) barrel.

          • Billy-bob Alexander

            I just got 80 rounds of Wolf 6.5 Grendel in from SGammo, haven’t headed to the range yet to try it out. I don’t believe my J&T upper is chrome lined nor nitrited. Wondering why you recommend this, as the steel case isn’t in contact with the bore, rather the FMJ (copper clad, lead core?) bullet is. Do you mean the chamber should be chrome or nitrite? I thought the lacquer finish helped with that. Just an honest question.

          • Komrad

            the case doesn’t matter at all, steel is a bit harder on the extractor/ejector maybe
            what does matter is the jacket
            a lot of steel case is copper washed steel jacketed
            a steel jacket wears faster, but not fast enough to really matter for range toys

          • Cymond

            Yes, it’s the jacket that matters, but I don’t remember ever seeing steel cased ammo with copper jacketed bullets. It’s easy to get sloppy when talking about the exact cause if the two variables are always found together.

          • ClintTorres

            Bimetallic jackets are the culprit but this advice is mainly for high-volume shooters. Typically, though, peeps who buy Wolf ammo buy it because they want to shoot in higher volume.

            Skip down to the bottom of this article for reference:


          • mosinman

            although to be fair they shot the manure out of the rifles and ran them hot

          • ClintTorres

            Yeah, no kidding, who does that much shooting? They dropped some serious coin to complete that torture test.

          • mosinman

            i hope to… over the course of a few years haha.

          • Billy-bob Alexander

            Thanks for the responses and the link guys. The Wolf Grendel is bi-metallic according to the AA website. I suspect those 80 rounds will last me a very long time so I won’t worry much about it. I just wanted a cheaper (plinking, coyote) alternative to the 123grain Hornaday SSTs I’ve been shooting in the Grendel.

    • Zugunder

      How about 7×62 chamber with 6.5 barrel? (I might sound silly, not sure what are this terms in English referring to).

      • Yeah, doesn’t sound like it’s translating well. Could you clarify?

        • noob

          maybe they want 7.62x51mm NATO case volume but a smaller more aerodynamic projectile in 6.5mm?

      • Ken

        If you’re talking about running a 6.5mm projectile on the case body from a 7.62×39, the 6.5 Grendel is already pretty close to that. The 6.5 Grendel’s parent case is the .220 Russian, which itself is a 7.62×39 necked down to take a .22 slug.

      • noob

        is the 6.5x55mm Swedish sort of what you

        want? http://en.wikipedia.org/wiki/6.5%C3%9755mm

      • DrewN

        Yeah, you are talking about .260 Remington or 6.5 x 51. Very similar performance to the 6.5 x 55 Swede.

  • Laserbait

    Doesn’t look like it would be, based on the shoulder location. I bet it does feed slick though.

  • Grendelfreak

    People have been fireforming Grendel brass from 7.62×39 for a decade simply by running it through a sizing die to resize the neck for 6.5 bullets, then firing it in their rifles, so I suspect it would be fine. It might not feed right in long mags because of case taper.

    And Wolf steel case is pretty close to steel case 5.56 and 7.62×39 prices, so I’m not sure it’s worth the bother.

  • Axel

    I don’t think it’s realistic that this cartridge would be implemented as a russian general purpose cartridge, but it is indeed very interesting that they are testing it.

    This is not viable as a special purpose Spetsnaz cartridge, like the russian resurrection of the 9.3 Brenneke, or the various silent or underwater cartridges. The point of this cartridge, at least in the entire western debate, has been to be a common cartridge for marksmen, carbines and light machineguns.

    RPK, AK and some form of DMR all using the same mags and ammo. Good move or not worth it?

    • Glad to see you on, Axel!

      Whether that sort of “universal” round is possible – the answer is yes, in the US Army’s case 5.56mm is used in all three roles. Now, what the optimum looks like for that is something I couldn’t say, but these larger caliber intermediates all have their own disadvantages.

  • Lance

    Id quite hoping for nothing Nathaniel You might see it for export but I doubt you see them for any government business in Russia.

    • I am happy with my 5.56s, actually. Just reporting the news.

  • Nicholas Mew

    I really prefer the on the taper of the 6.5 on the right. The taper that the Russian have chosen, while understandable is not really ideal in my opinion.

  • Chase Buchanan

    Second to last sentence: “a little big pregnant?”

    • noob

      like any small arms project, there is a high chance that it may miscarry.

    • I shamelessly stole that line from The Black Rifle’s chapter on US Army adoption of the M16.

      • Chase Buchanan

        I just meant I think you misspelled it.