Assuming you're referring to the M1903A6, it used the 7.62x63mm cartridge, more popularly known as the .30-06.
The .45 caliber bullet is not used in a sniper rifle.
Yes, I can. A Barrett M107 is a .50 caliber sniper rifle.
.408 CheyTac
The Dragunov (note corrected spelling) sniper rifle is in caliber 7.62x54mmR. This is the same caliber at the Moisin-Nagant 91/30 rifle.
No
The 950 JDJ is not intended as an ultra-long range cartridge. There is no sniper rifle in that caliber.
It's a good caliber, yes.
how far does a 50 caliber sniper rifle shoot accuratly
All of them.
5-10K or more
The Barrett sniper rifle typically uses .50 caliber bullets.
Buy a decent sniper rifle (gas or spring) a scope if it doesn't come with one and then practice.