Most places require you to buy their paint, so no.
The .50 Cal Sniper (Tip: aim for the head)
Yes. The .50 cal is one of many weapons available to the sniper, though there are several others, each of them favored based upon the type of sniper mission.
50.Cal.
quite big
Using a 40 cal pepperball in a 50 cal paintball gun is not recommended as it can cause damage to the gun and affect its accuracy. It's important to always match the caliber of the ammunition with the gun to ensure safe and effective shooting.
up to and in excess of 10000
The bullet itself - no.
They will "fit" but they will not fire correctly, and will break when the bolt tries to push two of them at once.
Barret 50 cal. all the way!
Depends on which .50 cal, and which cartidge. If you mean a Barrett Model 82A1 sniper rifle, in .50 BMG, standard ball ammo is ABOUT 2800 fps.
They both fire the 50 BMG