The Polish Special Forces support unit Jednostka Wojskowa Nil has ordered a batch of 27 60mm vz. 99 Antos ultralight mortars, following up a previous order earlier this year. MilMag has an excellent article detailing this acquisition and the features of the Czech-engineered Antos, which you can read by clicking the link here.
The 60mm Antos mortar, also previously branded the Norsk USA/DSG Technology iMortar in the USA, is a unique ultra-lightweight medium caliber mortar intended to be carried with light infantry and special forces. In contrast to existing mortars like the 60mm M224 which weigh over 20 kilograms when assembled, the Antos is much ligher, with a total system weight of only 5 kg (~11 lb). It achieves this through a novel design which eliminates the traditional bipod, reduces the mass of the baseplate (which is fixed, instead of removable), and incorporates the use of an innovative liquid sighting system that uses a body of liquid to indicate the ranging distance. Perhaps most significantly, the Antos requires only a single operator, where existing mortars require a gunner plus assistants. A video showing the Antos in operation is embedded below:
To illustrate how significant the 60mm Antos mortar’s weight savings could be, take the mass of a 3-man mortar team carrying 30 rounds. With the mortar plus ammunition, this arrangement weighs 63.1 kilograms, or about 21 kilograms per person. With the 60mm Antos, each member of that team could carry 11 rounds, an Antos, and fire it without assistance, for an equivalent load.
The Antos is not a replacement for the existing mortar, as it reportedly cannot duplicate its performance. Durability and barrel life of the Antos is apparently reduced, and the mortar is effective only to 1,230m, much less than the 3,000m + of the M224. However, it’s not difficult to see how incorporating mortars of this type into small special operations forces reconnaissance teams, or even at platoon level in a regular force during certain operations, would be a serious force multiplier.