66 Powermaster. bb 4.5mm. I purchased this bb gun at a pawnshop. The pump flops out without pumping it and it doesn't fire. Spent 30 dollars. There are brand new ones at Walmart that are only a little bit higher in price.
I used to fire pellet guns in NJROTC that are used in actual tournaments. I'm trying to find one that acts like that, it has a bolt action that is in real rifles. I also used to have airsoft m4 replica(no pic) that was automatic. An mp5 airsoft gun that was see through and automatic. A pistol that was realistic looking and not plastic, it was single shot. An m16 that was single shot, most accurate I've found for airsoft. I almost got shot by the police, they thought it was real.
I've played many airsoft fights in the back of my old apartments in thick trees and bushes. Real fun. Once we were in the middle of fighting and other people playing paintball came between us. We started to fire at each other in all directions. Not one of us got hit by a paintball. If we did hit them they really wouldn't feel it with their gear.