|The Bofors 57mm 70 caliber gun was first introduced in 1966 when it was fitted on the Swedish Navy’s Spica class fast attack craft. The Mark 1 gun had a 200
rounds per minute rate of fire and a 40-round magazine in the turret. An additional 128 rounds were stored beneath the deck. The Mark 2 was designed in 1981 and
introduced into service three years later on the Stockholm class corvettes. The Mark 2 had a slightly increased rate of fire of 220 rounds per minute. The Mark 2 was
housed in a new light weight gun turret and had a new gun barrel that was forged from monobloc steel, which eliminated the need to use a water jacket for gun barrel
cooling during firing. In addition, a new servo drive/servomechanism system was developed which increased reaction time and improved gun aiming and control. This
new system made it both accurate and agile enough for use against sea skimming anti-ship missiles.
The Mark 3 was designed in 1995 but introduced into service in 2000 with the Visby class corvette. The Mark 3 had the same gun turret, rate of fire and ammunition
capacity as the Mark 2, but an additional 1,000 rounds were stowed in a standby rack beneath deck. The most significant improvement was the fitting of a small
radome above the gun barrel which was used for measuring the muzzle velocity of the departing projectiles for fire-control purposes. Also, a new optional low radar
profile stealth mounting was developed, which allowed the gun to be hidden from radar. The United States Navy and Coast Guard have designated the Mark 3 as the
Mark 110 Mod 0 57mm gun and it is manufactured at the BAE Systems facility in Louisville, Kentucky. The Mark 110 Mod 0 57mm gun is fitted on the U.S. Navy’s
Freedom and Independence class Littoral Combat Ships (LCS) and the Coast Guard’s Legend class cutters.