Action Army 6.03mm AEG Barrel 310mm SHS They use a long serpentine

They use a long serpentine spring wound through a channel to hold and then push the BBs out

Dimensions: 12mm deep x 20mm wide x 121

Fits in the ARP9 airsoft gun only

and various models with or without rails

and turn the Laser On/Off

Action Army 6.03mm AEG Barrel 310mm SHS They use a long serpentineThe Action Army 6. 03mm AEG Barrel 310mm. Fits inside AEGs that require this length. This is a 6. 03 inner barrel diameter, so it allows for less jams and tolerances than the 6. 01mm. A very popular choice as an alternative to the Prometheus. One piece high grade metal machined. Precision smooth inner bore with nickel plating. This inner barrel is an upgrade to improve your gun's performance, accuracy, FPS, and range compared to stock gun barrels.