A couple of points. I never fire my tanks when my kids are around (and they are young and at time clueless when it comes to the dangers of airsoft guns) For a basic gun/barrel combo I charge $30 plus shipping. I believe its about $15 to the UK. I use 0.20g bbs as they fly slower (but straighter) and you can actually see them so you know where they are going. As well, wear safety glasses just incase of rebounding bb.