Another irony, surrounding the “war reserve ammo” reason to drop the .276 cartridge...by the time the Garand design was finally adopted (1936), the supply of World War I-era .30-06 was “officially” exhausted. Around this time, base-level repair shops were officially forbidden to continue using “ammonia dope” to remove copper fouling left in gun barrels by the cupro-nickel jackets of the old M1906 ammo.
Of course, that could also have been a convenient excuse to request funding for supplies of the new M1 Ball ammo....
(”Ammonia dope” is a chemical solution made up to dissolve copper deposits left by bullets. Done properly, it works very well...done improperly, it can destroy the barrel.)
I first heard about using window cleaner with ammonia to kill the corrosive salts in mil surplus ammo many years ago. I use it on my new guns now makes barrels sparkle just make sure it is dried out then lay the oil to it....