18+ all the way just like Greylocks has said.
Yes it will certainly piss some of the younger ones off but so be it. This is not about a popularity contest, its about keeping airsoft a viable sport for now and in the future, so the 16 year olds can still play Airsoft when they are 18.
Sorry all you under 18's, but please see the reasoning behind this.
As a side note, everyone who has joined and will join the South Island Rangers here in Victoria MUST be verified by myself to their age and NO under 18's are allowed. Positive proof of age has to be supplied, strictly for the reason as others have said, when you are 18 YOU are responsible for your own actions.