Production of treated wood with improved penetrability by projectiles is accomplished in an improved pressure treatment with an improved treating solution. The wood is impregnated in a pressure treatment process with a treating solution containing an impregnant, an aliphatic hydrocarbon or halogenated hydrocarbon liquid carrier, a cosolvent if the solubility of the impregnant in the liquid carrier is inadequate, and an effective amount of lubricating oil. After the treating solution has impregnated the wood, the liquid carrier is evaporated leaving treated wood containing an impregnant with internal lubrication due to the oil and possibly some cosolvent.