The C8 carbine is the carbine member of the C7 family, and in outwards appearance very similar to the Colt 653. Colt made the initial C8s for Canadian Forces as the Colt Model 725. The C8 has a 14.5-inch A1 profile barrel like the Colt Model 653 M16A1 carbine, but with a 1/7 rifling twist appropriate for the 5.56x45mm NATO C77 cartridge. The C8 incorporates the design improvements featured on C7 rifles. This design combines the accuracy of a full-length rifle (such as the M16) with the weight and rapid target acquisition of a compact carbine (such as the M4).
The improved C8A1 (Diemaco C8FT) is essentially the same as the C7A1, just in carbine form, and is currently the best carbine in the world. The overall layout of the weapon remains essentially unchanged except for the upper receiver and the general inclusion of the C79 sight. C8A1s have also been more commonly seen with the detachable carry handle with A1 sights developed by Diemaco for both the C7FT and the C8FT.
Building upon the C8 and C8A1, Diemaco created the Special Forces Weapon (SFW), which provides an interesting combination of ideas. Featuring a longer, 16-inch barrel of a heavier profile than the C8/A1, the SFW is designed to provide a fire support capability in carbine form. The profile of the barrel is not uniform, oddly enough bulging out at the end, whereas the M4 profile barrel steps down. The front sight base is strengthened for mounting of the Heckler & Koch AG-C/EGLM grenade launcher. The British Ministry of Defence acquired a number of SFWs, primarily for Special Forces, giving them the Land Force designation L119A1. This version of the C8 is also in service with the Norwegian MJK and HJK. Because of the barrel profile, another Diemaco specific mount is required to attach the M203 grenade launcher (though the MoD have decided to use the HK AG-C/L17A1).
Concerns that Princess Patricia’s Canadian Light Infantry had with the C8 led to the creation of the C8FTHB. The C8FTHB (Flat Top Heavy Barrel) features numerous improvements over the C8, including a heavy profile hammer-forged barrel and Elcan C79 Optical Sight.
Other C8 Variants
Recently, Diemaco has begun producing three additional C8 variants. The C8CQB similar to the Mark 18 Mod 0 CQBR, having a 10-inch barrel and a Vortex flash suppressor. The Diemaco Personal Defense Weapon (PDW) is even more compact having an overall length of 20.7 inches with stock fully retracted. It has a 5.7-inch barrel and the receiver extension has been shortened by 1.65 inches. A further upgrade upon the C8FTHB is currently being slowly integrated. The new version will be designated the C8A3. The C8A3 will combine the C8FTHB with the upgrades found on the C7A2. These improvements include green furniture, ambidextrous fire selector, magazine catch, and an extended ambidextrous charging handle.
Colt and Diemaco also paired up to develop a squad automatic weapon variant of the series. The Diemaco Light Support Weapon (LSW) features a heavy barrel suitable for sustained fire. The LSW can only be fired on fully-automatic. The LSW has a boxy square handguard with a carrying handle and a vertical foregrip that can be used as a monopod. The LSW was made with no bayonet lug until recently because of the original bipod. A new bipod attaches to the same barrel yoke as the carrying handle and front grip, so current LSWs are made with a bayonet lug. Unlike many M16 variants, it fires from an open bolt, allowing the removal of the forward assist. The LSW used by the Royal Danish Army fires from a closed bolt and also has a semi automatic firing mode. The Diemaco LSW was originally a license produced variant of the Colt 750, but both Colt and Diemaco have upgraded their respective weapons to include features like a detachable carry handle and other features separately. The Colt weapon likely has a new 900 series model number.