The Army is looking to increase the capabilities of the M109A7. By introducing the new XM1113 rocket-assisted projectile (RAP), it can reach from the current 39-caliber barrel, and a planned barrel extension to 58-caliber can increase its range to . An additional XM1113 improvement over the legacy RAP round is the replacement of the high explosive, TNT, with an insensitive munition that is less volatile and less prone to unplanned detonation. The Army is also working on an autoloader to increase sustained rate of fire to 6–10 rounds per minute. These improvements are being developed under the Extended Range Cannon Artillery (ERCA) program, with the upgraded system designated the M1299. The first ERCA cannons are planned to be fielded in 2023, with the autoloader fielding one year later. Another part of the ERCA effort is the use of a new super-charged propellant to fire the shells, which required redesigning the howitzer to handle higher pressures.