.264 Win Mag

[bosveldjag]

I am in the process of having a tailor made .264 Win Mag manufactured in South Africa by Truvelo for specific use on long distance shots on springbuck, blesbuck and swartwildebeest - all plains game, lots of open spaces and little bush coverage.
Some of the specifications are: 1:9" twist and a 27" barrel length.

Anybody used this type of rifle successfully under similar hunting conditions?
More detail on bullet types, loads, etc. would also be appreciated.