Shot size

Had an interesting discussion with Rick just now, about shot sizes for driven birds. I've used #5's (lead) with good results and have some #4's (did for Mr Mellie). Rick's convinced that 6's are the go. So I'm taking 200 rounds of 6's off his hands. It's a 150 bird shoot, 9 guns I think, so I'll shoot as many as fly my way and if I'm in a good spot I'll kill a big pile of them. Guy says that the standard of shooting this year has been abysmal on other estates, maybe this will be the same? he mentioned 800 rounds for 50 birds at rathmoy!!!!!! Could be a really long day!!!!!