BES Bullets can be contacted at mseller208@aol.com tell them that Nigel sent you!
They make both flat based 174 and 215 grain .303. I have tested some of the 174 in a No.4(T) and it shoots slightly better than Sierra MatchKing. They bullets are virtually hand made on a single stage press. Cost is £20 per 50. If you have a cordite shot barrel these bullets could probably extend barrel life by another 1,000 - 1,500 rounds. They shoot very well to 200 yards - not tested them further than that but I won a 200 yard McQueen's sniper comp using them. 48ex 50 with a 4" bull.
They have just started to make the original round nosed profile 160 grain 6.5mm. Shot some in my SwedishM/41B sniper and at 100 yards they shot to 0.36".