The Heckler & Koch SL8 is a semi-automatic civilian version of the Heckler & Koch G36. Depending on the model, the rifle uses the .223 Remington or 5.56x45mm NATO cartridge and 10-, 20-, or 30-round detachable magazines. This rifle uses a lug-type rotating bolt mechanism similar to the AR-18, not a roller lock bolt like earlier HK rifle models. The SL8's pistol grip and folding stock have been replaced with a fixed stock with a thumbhole, to make it more suitable for the civilian market. Additionally, the receiver has been altered to prevent the attaching of a folding stock. The trigger pull has been lightened, the cheekpiece and buttplate are now adjustable, and the barrel has been made heavier and more accurate. The free-floating bull barrel is cold-hammer forged with a recessed crown, made of cannon-grade steel. The SL8 variants: SL8, SL8-1, SL8-4, SL8-5, SL8-6, SL8-10, SL9SD, R8.