What is a 6mm bb gun used for i mean is it deadly or not ?

Question

can a 6mm bb gun kill a person if you fired off the gun a the bb hit them instead of the target

Answer 1

It entirely depends on the velocity of the gun.  If it's a 300 fps airsoft gun, then no, it isn't deadly.  If it's a 1,000 fps gun shooting steel 6mm BBs, then yes, it can kill someone.

Answer 2

Plinking, target shooting, varmits and pests.

Is it 'deadly'? To a cape buffalo - no. To a squirrel - definitely!