That would have been a Remington manufactured 1903-A3, I have a 03-A3 that was past down to me from my father a Smith Corona 03-A3 Date of manufacture 5-43 it has 4 grooves in the bore and also has been Sporterised but is also my most accurate gun I own, I can shoot SUB 1 MOA at 200 yards with factory winchester 150 grain silvertips ( not the ballistic tip). I now have handloads I make up for a local hi power Match here in my town I use a Sierra 175 grain BTHP Match bullets I can hold .5 MOA at 200 yards. They are great guns I dont know why remington made them in a 2 groove other then to cut cost towards the end of the war.