i bought an FAL yesterday, took it out and fired some rounds this afternoon, it throws the brass about 15-20 feet , is this normal? do i need to adjust the gas system, it's between 4 and 5 right now. and if it does need adjusted , how do you adjust the system? and i noticed the case mouths on the empties were dented pretty bad, my mini dents them sometimes, but not as bad as this.