22 LR up to and beyond 50 BMG
In California.
By which side? The US and its allies used 7.62x51 for their sniper rifles. The North Vietnamese typically used 7.62x54R for theirs.
Yes. You can get replacement springs for airsoft sniper rifles.
The manufacturer is spelled Barrett (Barrett Firearms Manufacturing), builder of the M82 and XM500 .50 caliber sniper rifles that fire the 12.7x99mm NATO round (Browning machine gun round).
It is often accepted the Heckler and Koch PSG-1 is the most accurate sniper rifle in the world.
Sniper rifles are just high caliber rifles fitted with a scope, if you are looking for a legal civilian good bolt action rifle i would stick with an m40a1, Remington 700, or M24, these rifles range from about 2,500$-10,000$+. If you want a nice semi auto stick with something like a psg1 or m110, m21's are good too, these rifles are usually 5,500$+ and chamberd for a 7.62x39mm round.
Also known as 7.62 NATO, this was the standard full powered rifle caliber for all NATO nations. Rifles included the M14, the British L1A1, the Belgian FN FAL, and even India had a bolt action version of the Enfield in that caliber. It is also used in the M60 machinegun, various sniper rifles, etc.
Paintball sniper rifles are sold anywhere ammunition and gun supplies are sold. Walmart carries paintball rifles and accessories as well in most of their stores.
The .45 caliber bullet is not used in a sniper rifle.
Local stores that sell guns or weapons will have a variety of information for an consumer with questions about sniper rifles. Academy and Wal-Mart are two different providers of guns and weapons who also sell sniper rifles.
It is believed that sniper rifles were invented around 1857 with the advent of the Enfield rifle. This rifle was then surpassed by the Whitworth rifle which became the first long range sniper rifle.
6lbs and up