My loaves seem to have good oven spring, I think. I think that because it rises up on the sides and forms an oval sort of shape each time. My cut often expands but doesn't open up much or form an ear.  Todays partly opened. I dont know if I am doing the cut wrong. Maybe too deep, not deep enough.  I do try and do 45 degree angle.  Does anyone have some advice to improve this please? 
given the advice, I tried the following:  sprayed water over the dough before putting it in the oven put a large thin metal pan on the shelf below the pizza stone when I turned the oven on put plenty of water into the pan 10 mins before putting the dough in first 20 mins had the pan in, then removed for another 20 mins.  here is the result will work on improving the cut, looks like I should have gone further deeper around on the left UPDATE so a few weeks on with more practice I have made some adjustments  spray the cut with a bit of water just before it goes in the oven put a large thin metal pan on the shelf below the pizza stone when I turned the oven on, I put the stone slightly to one side and the pan slightly to the other. (don't know if this helps, but helps with the pouring speed) Have the kettle fully boiled just before I am going to put the dough in the oven Put the dough on the pizza stone, THEN pour the boiling water into the hot pan underneath the stone and quickly close the oven door. do NOT do the main cut too deep, that seemed to cause  the bottom of it to go hard or something. At least the later, more shallow cuts seem to be doing better  this is how the latest loaf came out   