Buffer Tube for Wet Environments – Griffin Armament Maritime Extension

Innovation does not always have to be the biggest and bad-arse. Sometimes it can be the little things that go a long way. Qualifying for the latter is Griffin Armaments Maritime Receiver Extension for modern sporting rifles. Basically, its a standard extension, but adds more drainage holes to ensure the weapon system stays up and running after being submerged.

Instead of the common 6061, Griffin uses a 7075-T6 forging that is then machined to military specifications and then holes are added.

Those near the coast to just looking for that something extra can peruse them on Griffin’s website here.


Nathan S

One of TFB’s resident Jarheads, Nathan now works within the firearms industry. A consecutive Marine rifle and pistol expert, he enjoys local 3-gun, NFA, gunsmithing, MSR’s, & high-speed gear. Nathan has traveled to over 30 countries working with US DoD & foreign MoDs.

The above post is my opinion and does not reflect the views of any company or organization.


  • thedonn007

    This will help with all of those boating accidents that people talk about.

  • Bear The Grizzly

    They should have called the holes “lightening cuts” since that’s all the rage currently.

    • Giolli Joker

      Speed holes.

      • Tassiebush

        Glory hol…. Hang on I’d better stop before I get too distasteful

        • iksnilol

          No, just go on.

          Trust me.

          • Tassiebush

            I’d better not but if you search the term along with Steel Panther you’ll see a music clip that explores the concept well…

          • iksnilol

            Old chap, you sly dog you.

        • Evan Green

          Hahaha best comment yet.

    • All the Raindrops

      Lube spitters

  • TheNotoriousIUD

    99% of the guys who buy this would probably burst into tears if their precious baby got so much as rained on.

    • But…but…. “innovation”!

    • Vitsaus

      More like spilled their Starbucks on it. Ninjas don’t go near natural bodies of water.

      • TheNotoriousIUD

        The automotive equivalent of the AR is the jacked up, snorkeled, doors removed, winch equipped Jeep with enough light bars Stevie Wonder could drive it whose tires will never touch dirt and if they do it will be in the car wash five minutes later.

        • Bear The Grizzly

          Thank you. Every time i see a snorkeled jeep drive by without being covered in mud “In the Arms of an Angel” plays in my head.

          • TheNotoriousIUD

            There’s a $50,000 Jeep on my block that I have never seen with as much as a drop of bird sh-t on it.

          • JumpIf NotZero

            Considering the price of a loaded Rubicon is 40k, that’s really not anything special.

          • TheNotoriousIUD

            Yeah, I get it. You are too cool to ever be impressed by anything.

          • Grindstone50k

            Only 50k? Pleb.

          • Squirreltakular

            Maybe it’s a regular model with a butt-ton of aftermarket upgrades?

    • Cal S.

      Oh, please, we’d only cry for a couple hours. Honestly, we’re not THAT shallow…

  • sliversimpson

    Nyet, rifle is fine.

  • andrey kireev

    So essentially this introduces more ways for dust to creep into your receiver… got it !

    • Squirreltakular

      Dust probably isn’t too big of an issue in maritime operations.

  • Sledgecrowbar

    Not a bad idea, although really only modestly innovative, I’m more interested in it being 7075-T6. If you’ve ever machined both it’s easy to be sold on the harder metal for strength. Not that anyone is buttstroking with an AR, at least not smart people, but it’s a nice upgrade. I’m honestly not sure if this is a rarity, though, but I’d be confident saying the ultra-cheap tubes out now are definitely 6061.

    • Joshua

      7075 is the correct material according to the TDP.

      BCM, VLTOR, and Colt are the only ones using it I know of 100%.

      • Rick5555

        A lot of companies are using 7075 forged tubes. SW, Spike’s FN, LWRC, Delton, (on some of their models), Reason 7075 is forged, is it’s practically impossible to Extrude 7075 aluminum. So it’s forged. Where some companies fool people, is the advertised the buffer tube being Mil-Spec “Diameter” which means it’s a 6061 extruded buffer tube.

  • Joshua

    While nice, it won’t make your AR-15 OTB rated. You would also need a extractor support lug in the barrel extension as well as a flat chamber face, and a thick barrel.

    Otherwise the water obturation in the bore will detonate the rifle either way.

    You need all of those things for a true OTB rifle, and very few have them.

    • gunsandrockets

      What if larger than .223 bore? Such as .300 or 9mm?

      • Joshua

        Practically all .30 cal rifles are OTB rated.

        The issue is with the .22 size bore diameter. I believe that water obturation stops being a problem around .26 bore diameter, or somewhere around there.

        .22 caliber rifles have to have extra odds and ends to function with water in the bore. They just cannot easily drain water without uncorking the bore.

  • iksnilol

    Can’t you just take your normal buffer tube, drill it to all heck and then refinish it?

    • thedonn007

      You don’t even need to refinish it. Depending on the stock you are using, no one one see the holes anyway, and those areas are not wear surfaces.

  • Jeremy

    This is similar to a mod they did on the Colt Commando in Vietnam for the SEALS.

  • All the Raindrops

    Common 6061? 7075 is common for quality RE’s

    • Rick5555

      Most of the better AR’s are using 7075. If the rifle says. milspec buffer tube. Then it’s a forged 7075 aluminum tube. Not the trick some companies use, by saying, Mil-Spec Diameter. Then it’s a 6061 tube. 7075 can’t be reliably extruded, hence it’s forged. Forging and 7075 is twice as strong as Extruded 6061 tubes.

  • Old Fart

    Just for the sake of the argument, how is this superior to the PWS 416 Enhanced?

  • Grindstone50k

    And the added benefit of squeezing the grease off the buffer spring and onto your stock! Lubed stock!

  • schizuki

    1.6% increase in speed and 2.3% decrease in drag.

  • Ted Unlis

    Or drill yourself along with a dab of Aluma Hyde II and save 30 bucks.

    • Cymond

      Yeah, but if someone is already planning to buy a 7075 receiver extension, then this doesn’t cost much more.

  • supergun

    Looks like a silencer.