I was very fortunate to attend the very last Lecture by Colonel Peter Labett at the IWM a couple of years back, it was his last as he passed away on the train home. He had some great research and the lecture was very interesting. The development and History of the .303 round. I made some notes and the HBSA published their record so there is plenty out there.
Some of the information about exposed lead cores, lightning spaces/voids in the tips, the different rulesregarding use of different ammo which depended upon who you were shooting at etc and the last batches made nationally and on contract overseas.