Abstract-Gain length products up to gl w 14 for the J = 0-1 line of Ne-like Ar at 46.9 nm have been achieved in 15-cmlong plasma columns generated by a fast capillary discharge. Amplification in plasma columns up to 20 cm in length was investigated. The laser line intensity is observed to increase exponentially for plasma lengths of up to 15 cm, above which it is observed to saturate. The saturation behavior is discussed.