How do I ask for feedback?

[GapsGalore]

Yet another job rejection, although reasoning is a first (received too many applications for the job). I am getting nowhere. Did they even read my application? Can I write an answering email asking for feedback on my application documents? I've been so long out of work, I've had my cv checked by the job centre but I've no idea what anyone who actually works in HR thinks of it.
Is it really all luck? Do you connect with people mentioned in job ads on LinkedIn? I have only about 10 connections and they're all mum friends...

You can ask, but at the initial sift I don’t think it would be the most helpful feedback as a lot of it will just be lots of applications. What industry are you wanting to work in? I’d start adding recruiters from that area on LinkedIn, introduce yourself and keep on eye out for when they post jobs. Some are often willing to look at cvs and give some brief advice at least in my industry, I’ve had some recruiters be willing to look and say what to tailor ans they will have better advice than the job centre.