Steve
One of the best postal comps is the one run by Dorset, their air rifle postal has 10 or 12 divisions set on average and covers all from national squad level down to pure beginners. They run a summer and winter league, see their website on www.dsrpa.co.uk and the contact is Barrie Phillips on barrie@dsrpa.co.uk if you drop him an e he will put you on the distribution to get entries.