Modifications were the addition of a new optical sighting system, a hydraulic buffer to smooth out recoil during automatic fire, and a collapsing butt stock similar to the one already in use on the carbine versions of the M16.
32.
Like many AR-15 type rifles, such as the M16 / M4, the barrel is threaded to allow muzzle attachments such as a M16A2 flash suppressor, a six-position Magpul MOE butt stock and pistol grip.
33.
The other main improvements made to the SVU over the SVD include replacement of the butt stock, pistol grip, trigger and the mounting for the sight; and shortening the barrel by 100 mm achieved perfect balance for the weapon.
34.
The design of the weapon includes telescopic, red-dot and mechanical sights; cold-forged barrel; folding and adjustable butt stock; as well as the capability to semi-automatic, three round burst and full auto fire.
35.
The M4 was developed from the Harrington & Richardson bolt-action M265 sporting rifle, adapted to a sheet metal frame with telescoping wire butt stock, a 14-inch detachable barrel chambered for . 22 Hornet and the 4 shot detachable box magazine of the Savage Stevens M23D . 22 Hornet sporting rifle.
36.
Variants of the initial C1 and the product improved C1A1 were also made for the Royal Canadian Navy, which were capable of automatic fire, under the designations C1D and C1A1D . These weapons are identifiable by an " A " for " automatic ", carved or stamped into the butt stock.
37.
In the Marine Corps, the M240G is the predecessor of the M240B . The main differences between the two machine-gun variations is the picatinny rail system, hydraulic buffer inside of the butt stock to reduce the amount of recoil felt by the gunner, and the number of gas settings on the gas regulator plug.
38.
They made copies of the Sten's Mk 1 *, Mk II and Mk III, a " New Zealand Sten " ( a Mk II / III Sten hybrid, with sights and a fixed magazine housing similar to the Mk III ), then branched out into " hypothetical " Sten-guns with a " Rotary Magazine Sten " ( a Mk II Sten with a drum magazine attached below the weapon and wooden horizontal forward grip on the left side of the weapon ) and the " FRT Gun " ( a long barrel Sten with a wooden or Mk 1 * type butt stock, a drum magazine attached below the weapon and sliding ramp rear sights ).
