The availability of a good full auto BB gun is nothing new. They’ve been done before and they’re wicked cool. However, something better may have just come along: the Barra 400E from Barra Air Guns. It’s the first and only electric fully automatic .177 BB rifle. It is in a class all by itself.
Check it out.

“Designed as a modern sporting rifle with no frills and a clean frame. The 400e looks great out of the box but is still highly adaptable for you to customize and make it your own.” -Barra Airguns
Electric guns are easier compared to CO2 guns. With CO2 rifles, you run into some annoyances such as having a million CO2 canisters laying around, having to worry about ordering more, and squandering air at the end of the day to drain it if needed. Electric rifles take those issues to bed. You only have to worry about an electronic battery pack in the rear that is rechargeable. Two power packs for two guns and a charger and call it a day.
Automatic BB guns traditionally use CO2. However, 12G Co2 cartridges fed air guns are messy and lose power over time compared to an electric rifle powered by one single battery pack. This thing looks to be even more fun than a suppressed .22 with a binary trigger.
A battery pack is both rechargeable and cheaper than Co2.
Now to get to the fun stuff.
“The Barra 400e is the world’s first and only production full auto .177 BB gun powered exclusively by electricity. Featuring patent pending technology, this BB rifle is built with a CNC aluminum receiver and handguard. Highly accurate and customizable out of the box. Pick yours up today and make it your own.” ~ Barra Airguns (not to be confused with Barra Barra)
400E Specs
- CALIBER-.177 (4.5mm)
- POWERPLANT-AEG
- ACTION-Select Fire
- LOUDNESS-Level 3
- MUZZLE ENERGY-2 Fpe
- MAX VELOCITY-410 Fps
- SHOT CAPACITY-Includes 50 Round Magazine
- AMMUNITION-.177 Steel BBs
BB Rifle Build List
The 400E BB Rifle has the look, balance, and feel of a real rifle. Weighing 7.5 pounds, it pushes just over a pound more than a real M4A1 and sports a 19″ smoothbore barrel. It is pretty kitted out with a synthetic stock that has the air of a Magpul UBR. It also has a flat trigger, ambidextrous selector, a rear and front sight, picatinny top rail for optic mounting, and an aluminum M-LOK fore end for accessories.
With all that being said, while the 400E can be modified externally I wouldn’t mess with the internals as the manual specifically states “• DO NOT MODIFY OR ALTER YOUR BB GUN. Attempts to modify the BB gun in any way may make your BB gun unsafe to use, cause serious injury or death and will void the warranty. ”
Loading Up
Loading the magazines and rifle is pretty standard. To load the 50 round magazine simply load the bb’s into the included speed loader. Now close the cover and push the lock button to release the rod. At this time you can now push the speed loader feed onto the magazine feed and press down until full. The magazines seat into the rifle just as any of rifle, and releases with a standard magazine release.
Included with the 400E air gun, this magazine holds 50 bb’s and is easy to both fill and empty. A speedloader is also included in the 400E package.
BB Gun Battery
“One battery charge gets you over 1000 shots. Featuring patent pending technology, the 400e can maintain velocities ranging between 380 and 410 fps. The consistent velocity and engineering of the rifle allow for high levels of accuracy for a BB gun. With rates of fire between 500-600 RPM (depending on battery C rating), it’s fast enough to be fun, but slow enough to engage all your targets before needing to reload. With the included 50 round magazine, this gets you over 5 seconds on full-auto before needing a mag change. That’s over 4x longer shooting than comparable fully automatic CO2 rifles.” ~ Barra Airguns
The proprietary battery pack for the 400E can be purchased directly from Barra. It is recommended to have at least two to ensure that if one dies you have one that will be fully charged on standby.
Not all battery packs are able to charge the battery pack inside the 400E. Barra Airguns sells the correct battery charger on their website (and it can charge three batteries at a time). Use it for fun or training.
The battery and battery charger are not included in the rifle purchase but can be purchased directly from Barra Air Guns website.
Where to Find a Barra 400E For Sale
Note: The kit comes with one magazine, speed loader, and flip up sights but DOES NOT INCLUDE THE BATTERY AND CHARGER.
Another Barra 400E Review
Got a while to really get into the weeds? Check this out.

The first (and currently only) full auto BB gun.
This article first aired in October 2022.
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Too costly
Too expensive
I bought the Barra 400e, a spare speed loader, two batteries, a charger, battery meter and five magazines from Barra. Their customer service is outstanding. All of my emails were answered quickly and I am very impressed with the gun and the fun I am having with it. By the way, I am 75 years old.
I received my gun. Looks nice. Did not receive the charger and spare batteries I ordered with it. No charger at all. Thank you, Jerry Stohlman
Halve that price and I’d get one tomorrow.