It usually is a bolt action weapon, i.e., Grizzly, modeled after the early British WW2 anti-tank gun. Shoots an actual .50cal sized round but has an excellent buffer group in the stock to absorb the recoil. Max effective range is roughly 2000 yds. Max range for a .50cal slug can range up to 7000 yards! NOT a light weapon to be carrying around.
I think the rifles typically weigh about 35 lb. The other characteristic they have is the oversize muzzle-brake (to help reduce the recoil to manageble levels). A consequence is a VERY LOUD report.
Hi. Can you explain what the definition of caliber is. Is it the width or length of the bullet.