That is a Springfield rifle I believe.
100-1000 USD depending on condition, accessoires.
Remington Firearms Company during WW2
line up the target on the top of the front sight while sighting the front sight through the rear peep sight.
Yes, so long as it isn't an m5a1 and is the 1905 model you should be fine.
If truely unfired and not an arsenal rebuild, it would probably sell for $1500.00, however if the serial number fell into the range of rifles that were designated as sniper weapons, value would exceed $7500.00
http://www.surplusrifle.com/03a3/operations.asp
50-600 or so
None of the 03A3's are antigues
03A3
Surplusrifle.com has a detailed, step by step process. Look for the links on the left side of the page under the Maintenance heading. http://www.surplusrifle.com/03a3/index.asp
To type the sigma symbol (Σ for uppercase and σ for lowercase), you can use different methods depending on your device. On Windows, you can use the Alt code by holding the Alt key and typing 228 for uppercase (Σ) or 229 for lowercase (σ) on the numeric keypad. On Mac, you can type Option + W for σ and Option + Shift + W for Σ. In many word processors, you can also insert symbols from the menu or use Unicode: U+03A3 for Σ and U+03C3 for σ.
It depends somewhat on your definition of "new", but basic infantry weaponry in World War II for the United States Army used only two weapons from Wordl War I in the regular footsoldiers equipment: The M1911A1 Colt automatic pistol, and the Browning Automatic Rifle (BAR). The 1903, and 03A3 Springfields of World War I were also used, but as sniper weapons, not as main infantry shoulder rifles. The basic shoulder rifle was the M1 Garand (1936), the secondary support shoulder weapon was the M1 Carbine, the submachine guns were the Thompson submachinegun, which missed, literally by days, being used in World War 1, and the M3 "grease gun" submachine gun. The bazooka was also a new weapon in WW II.