Do Airsoft bullets hurt?
The pellets shot from Airsoft Guns do sting when they hit you on bare skin, the baggier or tougher the clothes are the less you're going to feel it. Depending on where you get hit, and the power of the gun it can range from stinging to really hurt.
An Airsoft sniper can really hurt due to their high power, which is why most Airsoft sites typically have a minimum engagement distance. In CQB however the pain is less of a problem as most sites in the UK have a hard limit of 350fps. It'll still sting if you get hit, but wont hurt for too long.