Century had their Sterling semi-auto carbines in 9mm and- much more interestingly- 7.62x25mm. One version had full-length heat shield. While I'm sure some folks think it looks cool, the full-length heat guard gave the carbine bad balance. The 7.x62, and the 9mm without the full-length guard, had very nice balance right around the support hand.
(The 9mm has the curved magazine.)