Is it true that at masters if you got in the 60's for you undergrad 3rd year you should expect around the 50's in terms of marks for masters work for msc?

I have never come across anything suggesting that (I have two masters degrees), but I have found mark schemes vary from university to university, Are you doing a masters at the same place as your undergraduate?

No was at Durham now at Lancaster.

I think you will find there will be a big difference in how much work you need to put in to pass. For example, I found my UG course much more difficult to the Masters. My UG degree was from one of the "red brick" unis and the masters uni is ranked in the twenties.

Ditto. I have an under grad degree from a bottom 10 red brick and had to work pretty damn hard to get a low first. I am now at a top 10 uni and work alot less hard to achieve similar grades. It might just be that I am not quite such a tight arse swot anymore though so maybe my grades have improved as I am not uptight about my grades, etc

At the uni I recently graduated in, my advisor told me students who got a 2:2 (under 60%) all got distinctions. Anyway it doesn't depend on your mark (unless you did so badly you don't know your stuff). It depends how hard you work and how well the uni teaches etc.

It depends on the subjects you choose for your undergraduate and for your Masters. At Masters level you probably may do better as you are probably more aware of your strengths and weaknesses.

As a undergraduate I did subjects that I had no flair for and basically it was a struggle. I also found doing exams difficult. I love to write and do research. As a result I only got a second class honours on my primary degree but got a 1st on my masters