FA-23 Assault Rifle

Created by Theo Gustin. STEP files included.

The FA-23 (Fusil d'Assaut-modèle 23) is an assault rifle based on the SIG-550.

It's chambered for 5.56mm NATO and features a 20in barrel with a twist rate optimized for the US M855 but this can be changed with a different barrel. The working principle consist of a gas-operated long-stroke piston with a rotating bolt locking itself in the barrel extension (like an AR15). The bolt catch activates via the magazine follower when the magazine is empty. The receiver is steel and the stock, hand guards and grip are polymer.

Magazine is a 30 round clear polymer. The stock can fold to the right side of the gun and the trigger guard can be rotated to allow the use of gloves. A picatinny adaptor can also be mounted on the upper receiver to use various optics. The iron sight uses a drum like the SIG, with 4 positions plus a night sight on the 100m (1) position and a folding sight at the front.

The FA-23M has received some improvements. The lower handguard is reinforced and can fit a picatinny adapter. The magazine is reinforced and the mag well is modified to suit it. The barrel has been modified to permit the use of rifle grenades.