Iran has unveiled its first two locally-designed and built self-propelled artillery pieces. Thunder-1 uses a 122mm barrel, while Thunder-2 uses a 155mm type. The former is copied from Russian artillery and the latter from US artillery. The Thunder-2 looks somewhat like an M109 (the Shah bought 440 of these prior to 1979) but clearly has a new chassis and turret rather than outright copies. The Thunder-2 has a maximum range with standard ammunition of 18.1km and a maximum rate of fire of four rounds per minute.--Stephen V Cole