I have a M1922M1 Army training rifle (not the DCM / NRA sales type). It does NOT have the caution as to "long rifle cartridge only" use on the left side of the barrel. The barrel is dated "S.A. 1-25". As all of the .22 cal. M1922, M1922M1 and original M2 barrels are the same, why no caution. Was this added after production started? Are M1922s so marked ?.