Russian 57mm AutoCannon Turret:
The Future Caliber or Relic from the Past?
The Franco-Russian cooperation for an IFV was recently revealed. It's an 8x8 vehicle called Atom.
One of the features that got quite a bit of attention is the 57mm main gun in the two-men turret.
The turret is called AU-220. It's been initially developed as an upgrade to the PT-76 amphibious tank to replace its 76mm main gun and old turret.
An upgraded PT-76 is shown with the 57mm AU-220 turret.
57mm Gun
The 57mm gun that's also used in Atom 8x8 is basically an Anti-Aircraft gun used in S-60 towed AA system. The gun was developed in 1950's.
In the AA configuration the gun is fed by 4 round clips. The same gun in the S60 AA mount is shown below.
The same cannon also used in ZSU-57-2 SPAAG vehicle.
The cannon uses 57x347mm semi-rimmed ammunition. The image below shows the 57mm ammunition vs the Bofors 40x365 ammunition.
The gun is recoil operated. Rate of fire is 105-120 rpm and the muzzle velocity is around 1.020 m/sec. It has a barrel length of around 4.4m.
The effective firing range against ground targets is 4km's.
AU-220 Turret
The turret is of Two Men configuration and weighs around 3.5 tons. The main armament is the 57mm rapid fire cannon.
The gun has a new automatic loading capable ammunition feed system that houses 20 ready-to-fire rounds as shown below.
The turret basket has a powered 73 round ammunition carousel that provides ammunition to the linkless feeder above.
The 57mm gun with the AP round has a penetration capability of 130mm of Steel at a range of 1.000m. I would expect the penetration would be much better for the huge 57mm caliber.
The 35mm APFSDS round has 120mm penetration at the same range.
This does not mean a lot at first glance, and you can think that the 57mm is still better than 35mm.
But when you think about the 35mm round doing all this with only 22% of the mass of the 57mm, one thinks that the 57mm caliber needs new ammunition in the APFSDS type to become a serious contender in the medium caliber market.
©WarfareTechnology 2014
