Electrothermal-chemical (ETC) technology is an attempt to increase accuracy and muzzle energy of future tank, artillery, and close-in weapon system guns by improving the predictability and rate of expansion of propellants inside the barrel.
Several countries have already determined that ETC technology is viable for the future and have funded indigenous projects considerably. These include the United States, Germany and the United Kingdom, amongst others. The United States' XM360 (cancelled in 2009) was reportedly based on the XM291 and may include ETC technology, or portions of ETC technology. Tests of this gun have been performed using "precision ignition" technology, which may refer to ETC ignition.
The XM-291 is the best existing example of a working electrothermal-chemical gun. It was an alternate technology to the heavier caliber 140 mm gun by using the dual-caliber approach. It uses a breech that is large enough to accept 140 mm ammunition and be mounted with both a 120 mm barrel and a 135 mm or 140 mm barrel. The XM-291 also mounts a larger gun tube and a larger ignition chamber than the existing M256 L/44 main gun.
Through the application of electrothermal-chemical technology the XM-291 has been able to achieve muzzle energy outputs that equate that to a low-level 140 mm gun, while achieving muzzle velocities greater than those of the larger 140 mm gun. Although the XM-291 does not mean that ETC technology is viable it does offer an example that it is possible.
