.50 GI AR-15 Uppers

AR-15 owners will soon have another “point five-oh” option for their rifles: the .50 GI. Before now only 1911 and Glock conversion kits were available for the cartridge.

The .50 GI was born out of the idea that if .40 was better than 9mm, and .45 was better than .40, then .50 must be better then .45. It should not be compared to the .500 S&W, .50 Beowulf or the .50 Action Express as it has much less power. The cartridge is comparable to the .45 ACP +P cartridge, but with a larger diameter bullet.

8″ SBR with .50 GI magazine.
Carbine with AR-15 magazines converted to take .50 GI

The .50 GI magazine holds 14 rounds and the AR-15 magazine holds 9 rounds.

The 16″ upper will sell for $750 and with one magazine. You can see the contact details of the manufacturer, RMW Xtreme Inc., at the beginning of the below video.

The 8 inch SBR chambered in .50 GI

Thanks to Giesler for the link.

Hat Tip: Photos from 475AR @ .50 GI Forum

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • SpudGun

    9mm then .40 then .45 and now .50 – with that train of reasoning, I fully expect to buy a .75 AR-15 upper by next April.

    If I had a dollar for the number of times I’ve wished I could fire a .50 pistol cartridge from an AR-15, I’d have .37 cents.

  • Matt Groom

    Finally, a practical use for the .50 GI. I would buy one. This would make an excellent SBR PDW.

  • Carl

    What’s wrong with the .50GI as a pistol caliber? Assuming the .45ACP is a good self-defense caliber a bigger bullet should be even more effective, right? And as long as it fits in a single stack pistol magazine I don’t see why not.

    Is larger than 50 caliber weapons legal in the US? I think there is some upper limit for rifles at .50 (BMG). Does this apply to handguns?

  • Matt Groom

    I believe I’ve read in one of the glossies that the law says you can’t have anything bigger than .520″, which means you can have things like a .512″ diameter bullet in your .50 Alaskan or something and still be legal. .512″ is actually about 13mm, so maybe the law actually says “Nothing bigger than 13mm…” or something.

  • Carl

    Ok, thanks for replying, Matt.

  • 475AR

    Yes, the AR is a great platform for the GI, as can be seen in the video the recoil is stright back and very little muzzle rise. With the 1-4 power scope on it I never have problem watching the target during recoil. It seems now when going to the range I shoot the GI more then any of my AR’s.

  • I bet that would be fun in a SBR.

  • I believe the Federal Law is the maximum bore diameter is .5 inches or .50 caliber for centerfire rifles, for civilian use anyway.
    (personally I think the 2nd amendment should cover any “arms” despite size, type or style, and since it incorporates “militia” anything used by the military should also be available to civilians, but that’s another subject)

    Muzzleloaders are exempt from most Federal Firearms Laws and can be had in larger calibers, .54 and .58 for example.

  • Chris Oberg

    This would be a great compliment to the Guncrafter .50GI
    and Glock/Guncrafter .50GI conversion
    Thanks for promoting the .50GI cartridge.

  • Clark

    The 9″ gun resembles MGI’s multi-caliber AR system, the Hydra. Look at the lever on the bottom of the handguard…

    It this a switch-barrel gun?