M1299
The M1299 is an American prototype 155 mm turreted self-propelled howitzer developed by BAE Systems in 2019 under the Extended Range Cannon Artillery (ERCA) program. It is based on the M109A7 self-propelled howitzer, and was primarily designed for the purpose of improving the M109's effective range. History. The Extended Range Cannon Artillery program was designed to produce a self-propelled howitzer system with an improved range and rate of fire compared to the existing M109A7 howitzer, in response to developments of Russian and Chinese artillery systems, which had become capable of outranging American systems. During tests  conducted in 2018, the M777 howitzer was able to double its range through the use of higher energy propellant and rocket-assisted projectiles; hitting targets over away. Using the same principles, the Extended Range Cannon Artillery was developed. BAE Systems was given a $45 million contract in 2019 to incorporate the ERCA's cannon into a M109 chassis, which was unveiled at that year's Association for the United States Army. Increased range and accuracy is accomplished by having a longer barrel, at 58 calibers long, and by using the XM1113 rocket-assisted artillery shell. In 2020, the ERCA  successfully hit a target away, which is over twice the range typically achieved by an M777 using the same round. According to the United States Army, the howitzer is planned to be completed in 2021 and will undergo operational assessment in 2023. It is expected to be fitted with an autoloader in 2025, which could increase its rate of fire from 3 to 10 rounds per minute. Design. Gun system. The M1299 is armed with a new 155 mm L/58 calibre long (a 9.1 m gun tube) XM907 gun that will fire the XM1113 rocket-assisted round. This will give  a range of over 70 km – much greater than the of the M109A7 Paladin. When fitted an autoloader will allow rates of fire of up to 10 rounds per minute. Originally the autoloader was planned to carry 31 rounds and be in service by 2024, but as designed it was too large for the vehicle, so it was reduced to a 23-round capacity for better weight, center of gravity, and "onboard kills".