Current expectations are mixed at best for this season; despite a relatively benign winter, the vast amounts of rain in April-June has impacted breeding success on some moors quite heavily. The last few seasons have indeed been very positive - I have had the honour of doing some walked up grouse days over pointers in 2009 and 2011 and both times were incredible experiences and enhanced my respect for the red grouse yet further.
Re the comment by the OP about Euston, the Caledonian Express train does still allow you to get up to the moors for the 12th/13th but there are very few doing it. I have done it twice and it was a superb method of travel - but given that I was told that I was only the second person to highlight my travelling up for this reason (when gaining formal permission/authorisation to take firearms on the train), there won't be any return to the pre-war days!
Re rearing of birds, and as other posters have mentioned, the red grouse is an entirely wild bird. The few attempts made to rear them (some in Southern England) have generally failed badly and quickly. Wild grey partridge can occasionally be reared, but again with mixed success and the very few estates which do have a harvestable surplus of wild grey partridges make very significant efforts at habitat and predator control vs rearing. Those in Southern/Eastern England which I know have a real passion for this and their efforts over many years have been rewarded.
