Review: New Strike Industries Mega Fin XL Rail

I keep in pretty close touch with the folks at Strike Industries and I have to say not without good reason. Strike turns out more innovative and downright great products than just about any company I know of.  It seems every few weeks I get word of another interesting product they are working on. This time it’s a new rail system for the AR. This one is the “Mega Fin XL 10 “inch. I was fortunate enough to be given the first one to leave the factory so you won’t see it anywhere else for a short time.


Note the small screws securing the rail to the receiver.

Note the small screws securing the rail to the receiver.

This is a keymod rail with a full length top rail in the heptagonal shape. As with all the Mega Fin models it uses numerous fins internally to aid in heat dissipation. It also has three QD swivel locations, one on the bottom and one on both sides. Another great touch is a built in front sight which folds flat into the top rail similar to the Tavor front sight. An installation wrench is provided at no extra cost. I also spoke with the owner and this rail system will be available in your choice of M-Lok or Keymod.

Installation is as simple as usual for Strike rails. Strike uses a proprietary barrel nut which is very easy to index. The rail is pulled snuggly over the barrel nut then secured using four hex screws. There are also two small hex screws on each side that provide further secure attachment by clamping the rail onto the receiver. That’s really all there is to it. It takes about 20 minutes to install depending on how familiar you are with the AR platform. I also replaced the gas block with a Strike version and melonite coated gas tube.


Flip-up front sight. Co-witnesses well with my EoTech.

Flip-up front sight. Co-witnesses well with my EoTech.

Now that the free float rail is attached I added a small rail section on the bottom and installed a Cobra Tactical grip. This is another well thought out accessory which gives the shooter several options for a secure grip not to mention the lateral lined front which allows the shooter to lay the weapon on a rest and push forward providing a secure rest to improve accuracy on longer shots. The grip also helps prevent the shooter’s hand from being placed too far forward on short barrels and wounding the support hand as we’ve seen so many times on other short barreled guns.


» Incredibly lightweight
» No gunsmith required
» KeyMod on all sides
» Free Floating handguard
» Full 7 angled Heptagonal Key-Mod system
» Mega Fins heat transfer dispersal technology


This new rail will be available in several lengths. The price will be announced but I imagine it will run in the same range as other Strike rails at approximately $160.00.

I really like this rail! Most rails aren’t all that aesthetically pleasing but this one looks good on the AR. I used this rail on a new build I had planned. A review of the build will be posted soon.

A small screw allows height adjustment.

A small screw allows height adjustment.




Phil White

Retired police officer with 30 years of service. Firearms instructor and SRU team member. I still instruct with local agencies. My daily carry pistol is the tried and true 1911. I’m the Associate Editor and moderator at TFB. I really enjoy answering readers questions and comments. We can all learn from each other about our favorite hobby!


  • BattleshipGrey

    I like the built in front sight. Not that I’d use it, but I like its integration. I’d have to see a
    15″ version to decide if I’d give it a go.

  • Tet

    Looks nice. I’ll purchase one when the 13″ becomes available.

  • Axel

    I’m so tired of seeing the words “lightweight” without the actual weight of the item listed.

    • GettoPhilosopher

      Yup. Every $&#ing part ever sold is billed as “lightweight”, but they never actually list the weights.

      TFB, please invest $20 in a postal scale.

  • Christian Hedegaard-Schou

    What on earth is the function of a melonite gas tube? What could the nitride finish possibly accomplish that the normal stainless tubes that have been in service for 50-freaking years can’t?

    • Timothy G. Yan

      It’s in black color and scratch resistant.

      • Yp just wanted the black color and yes the scratch resistance.

        • Timothy G. Yan

          Not sure how useful for the general public but nitrided gas tube is great for gun writers since we changing hanguard and other stuff all the time.

          • Very true and no doubt this one will change yet again. It’s also harder to be seen when you photograph a rail system and don’t want the gas tube to reflect light.

    • Frank

      Remember those 5.45 AR uppers had them because they tend to not rust from corrosive ammo. There’s not exactly corrosive 556 laying around, so I’m not sure what the point is.

      • Timothy G. Yan

        AR gas tubes are made from stainless steel so corrosive ammo is not a problem. However, on all the 5.45 cal AR, usually the barrel, gasblock and the BCG are nitrided. So, the gas tube is probably nitrided as well.

        • Frank

          I don’t now where you’ve been. Bare stainless steel can and will rust. Especially when exposed to the salts of surplus corrosive ammo. Anything shy of nitrogen steel will rust given the right circumstances.

          • Timothy G. Yan

            The Russian did fine with just Parkarizer internal and the Yugo with unlined barrel. So, just clean your weapon after firing corrosive ammo. Oh, yes I have fire corrosive ammo through an AR with the plain gas tube and no rust yet.

  • Brad

    Are they going to release that damn block locking block?

  • Grindstone50k

    Picture of the barrel nut?

  • RPK

    Melonite was popular back in the late 50’s and early 60’s. You would think by now arms manufacturers would have progressed far beyond this level of technology as an application for the gas tube.

  • Tierlieb

    “Heptagonal? You keep using that word…”
    And octagonal rail with 7 surfaces covered with keymod slots does not become heptagonal. Marketing does not beat math.

  • Cymond

    I really like Strike Industries. They release so many products so often that their designers must stay very busy. I’ve read that Magpul released products at a high rate when the were a young company. However, I do think it’s a bit silly that SI has 7 different brakes/comps. I don’t see any comparisons of performance, so I feel like we’re supposed to just pick one (for looks).

    So what makes it XL compared to the G2 handguard? Is it just feature-rich, or is it physically larger or something?

    Try to get them to publish the weights, though. They published them for the Mega Fin G1 and the drop-in Mega Fin, but not the Mega Fin G2.

    I wish SI would get official clearance for their Cobra grip on pistols. It should be legal since the Magpul AFG is, but never assume the ATF will be fair or consistent.

    After a lot of debate, I’ve decided to install either the SI Drop-in Mega Fin or the Fortis Rev-2 because I really don’t want to mess with the barrel nut on my Bravo Company upper.