Hi,
Not too sure i can help but im only aware of 2 ranges of any description in or around Chippenham, the first is on an old RAF camp just over the M4 called Hullavington. The other is at the barracks in Colerne not 100% on Hullavington but Colerne is def 30m (95% probable that Hullavington is too)
Will have a look on me map
HTH,
Dave.
**Edit** Oooops, forgot to mention Rudloe Manor. Only been there a couple of times (not to shoot) and i assume they must have one too.
In fact capitalisation is important all the time. It's the difference between "I helped my Uncle Jack off a horse" and "I helped my uncle jack off a horse"