Yep. Parkerizing became popular during WWII.I'm going to step out on a limb here without consulting the wiki link. The original 1903 Springfields were blued. The 1903-A3's and 1903's that were rebuilt after WWI were Parkerized.
OBOY! The experts are weighing in!! Learning cap ON!Eddystone began parkerizing their M1917 rifles in September 1918.