We present calculated and measured parameters of XeCl lasers with 25 - 25 cm aperture pumped with two electron counterbeams. The optimal mixture of Ar:Xe:HCl = 700:10:1 at a total pressure of 2.5 atm provides for the following lasing characteristics: energy of the emission pulse (duration 250 ns) measured at half maximum level exceeded 200 J, the gain of weak signals g0 was 0.065 cm-1, the unsaturated absorption coefficient α0 = 0.015 cm-1, and the laser efficiency with respect to the amount of energy deposited into the active medium was 3%.