Gazzer, how far south are you?? At Shoebryness there is an MOD Artillery closed test area. That has hundreds of achres of 'open' land. They are willing to allow civilians on to the area for 'dangerous' rocket testing. You would have to contact them first and speak to one of the leasion officers there, but I have found that they would welcome your "test" days and you would have a very good audience . There is also Salisbury plain which has no access restricions other than gated entry which is only manned on live fire days. Again speak to range control in Larkhill over access.