We have found the following BBs work well in the 400e:

Air Venturi 

Black Hornady

ASG Blaster

Umarex Steel BBs

Not all BBs are created for the same purposes. BBs vary in 3 major areas: size, tolerance range, and finishing texture.

The most common reason for a BB jam is the BB in the magazine does not line up correctly with the barrel. To correct this, drop the magazine and let the
jammed BB drop. Sometimes during shooting, the rifle may stop unexpectedly. Release the
magazine, reload the magazine and try again.

If a BB is jammed in the filter ring follow the steps below:

Watch Video

1. Remove Magazine, clear any excess BBs
2. Remove battery (safety first!)
3. Remove front pin by driving it out with a pin punch and separate receivers
4. Remove and set aside dust cover plate
5. Loosen the screw at the back of the bucking system
6. Remove filter ring and clear jam completely
7. Reinstall filter ring, dust cover plate, and screw
8. Line up receivers and drive front pin back in

If a BB is jammed in the filter ring follow the steps below:

Watch Mag Clearing Video

The minimum battery requirement is 11.1v, 3s, 1800 mAh, 25c Lipo brick style with a Deans connection.

Make sure the BB gun is on "SAFE" UNLOADED, and pointed in a SAFE DIRECTION.

Push the release button on both sides while pulling the back cover.

Securely connect the battery leads.
Insert the battery into the stock and replace the cover.

Load steel BBs into speed loader.

Close the cover, Push the lock button to release the loading rod.

Insert the magazine feed to speed loader feed.

Push the loading rod until the magazine is full (DO NOT APPLY
EXCESSIVE FORCE).

NOTE: If you want to load an “empty” magazine into the gun, please push the BB follower back into the magazine before you insert it.

Locate the safety on the left side of the receiver.

Turn the lever to "SEMI" for semi-auto mode.

Turn the lever to "AUTO" for full-auto mode.

The BB gun is off "SAFE" and ready to fire when pointing to either
"SEMI" or "AUTO."

Once in desired mode, point at predetermined target and pull trigger.

Front and rear sights flip up easily from mounted position. To unmount or move sights, use a hex key to loosen the right side of
the mount until you can move the mount to your desired location. Retighten mount. Turning the rear sight wheel will adjust the left and right mounting & position of the sight.

Extend the length of the butt stock, press the adjustable stock
spring in and pull backwards. The stock adjusts to 6 positions.

There are several causes for your gun to have no operation. Below are some of the causes along with recommended actions.

Fire selector is set to SAFE - Set the fire select switch to semi or full-auto.

Battery is not charged - Fully charge the battery.

Battery connector is disconnected or reversed - Connect the connector correctly.

Poor motor connection - Check and repair the motor connections.

Expired motor life - Replace a new motor.

If the motor is running, but no BBs fire from the gun, this can be due to a few issues. First, please check your gun to make sure that the magazine is fully placed in the receiver. If not, load the magazine into receiver and turn the gear wheel. If it still doesn’t work, contact customer service
and ask for assistance.

Another cause for your gun not to shoot BBs when the motor is running is that the gun may have a faulty gear or levers may be broken. If you think that this may be the case with your gun, please contact customer service and ask for assistance.

If the full-auto mode is not functioning on your gun, this could be due to a couple of different issues. First, please check to make sure the gun's battery is fully charged as, insufficient battery power affects the gun's ability to shoot.

Another reason for the gun to not function properly in full-auto mode is that there could be a faulty feed of BBs from the magazine causing a jam. Use the cleaning rod to remove jammed BBs.