EtronX is
Remington's solution to providing the shortest
lock time possible.
This rifle will fire the cartridge only .0000027 seconds after the trigger breaks!
To do this, the ignition system was totally changed, instead of a mechanical striker/sear/hammer mechanism it uses an electric charge to set off the primer of the chambered round.
It uses special cartridges for this and I am guessing that they are extremely expensive due to the still exotic nature of this technology.
According to Remington, the shorter travel required by the trigger to break also resulted in a rifle that has a very short and very crisp trigger pull.