Product Features & Specifications FN 36100608 FN 15 SRP G2 5.56x45mm NATO 16" Black Barrel/ Receiver 30+1, Black 6 Position Collapsible Stock, Black Polymer Grip, Optics Ready The FN 15 SRP G2 is a lightweight carbine with maximum 12 o'clock rail space. It uses a M16 style bolt carrier, bolt MPI inspected and marked. The SRP G2 features a free-float handguard, button-rifled barrel with an A2-style compensator, and a 6-position collapsible stock with sling mount.