Transitioning into HR

Hi Everybody I'm trying to transition into a HR role and I would be greatful for some advice for applying for my first HR role. I've just completed a MSc in HRM and acheived my Assoc CIPD. My current job is very different from HR, I've worked in an operational civilian role in roads policing for the last 15 years so hopefully have some transferable skills. I'm quite a low grade (non supervisory) but as I've been there the longest I do all the training for new starters in my team. I'm also been a school governor for the last 5 years at a federation of two large primary schools where I chair the committee responsible for HR and finance. Although they are big school they are small organisations with less than 100 employees and our executive head teacher is very experianced so most problems are managed before they become formal HR issues. I've started applying for HR jobs a few months ago but so far I've only had one interview. When I have had feedback for jobs I didn't get an interview for they have said I've not got enough experiance but how can I get experiance if I can't get a job? Thanks Matt