The lineup for cheap surplus .303 is getting longer all the time. I have yet to see any online ammo seller selling .303 for cheap. My definition of cheap is 50 cents or less a round. Your best bet is to go to gun shows and browse the ammo tables. There are guys out there who have war surplus of 50's vintage ammo that are still selling for 50-60 cents a round. Too bad we can't buy ammo from the US as there still seems lots of cheap .303 there. Just my 2 cents worth