I was asked earlier about loading for the .303. I have an old Lyman manual from about 1967. It's the first loading manual I ever bought and the one I used when learning to load. I still use it, along with others. It has great information about some of the older rounds, such as the .303 Brit, including loading data for the 215 grain bullet. Here's a scan of the .303 page some of you may find helpful:

The last load I was using is 38.5 grains of IMR4895, Woodleigh 215, Fed 200, Remington brass, OAL 3.075". This is a mild and accurate load that seems to approximate original ballistics of the 215 grain loading.

Curl