I still am a "Greenhorn" when it comes to 03 A3s. I know that both Remington and Smith Corona made 03 A3s, but I am confused about what rifles had how many barrel grooves. I have heard of 2 groove barrels, 4 grooves and even 6 grooves. Approximately when were these different configurations used by the two manufacturers ? Why did they change the number of grooves ? Did any of the barrels provide a higher degree of accuracy ? Thanks