The 303 is one of my favourite cartridges and the Lee Speed styled sporting rifles are definitely my favourite stock configuration.
This is a coupe of threads on some I have done

http://castboolits.gunloads.com/showthread.php?246222-A-Lee-Enfield-Sporting-rifle

http://britishmilitariaforums.yuku.com/topic/19093/Bills-Lee-Speed-cure#.VqVqsORunIV

And then there is these two with one being a 375 and then mine in 400

http://forums.nitroexpress.com/showflat.php?Cat=0&Number=260603&page=0&fpart=1&vc=1

The martini makes a great little 303 as well even in the original military configuration
http://castboolits.gunloads.com/showthread.php?226756-A-Martini-Enfield-303-again

But it much nicer in the sporting stock
http://forums.nitroexpress.com/showflat.php?Cat=0&Number=273104&an=0&page=0#Post273104

Last edited by VonGruff; 01/24/16.
Von Gruff.

Exodus 20:1-17

Acts 4:10-12