Thanks Martin, and good luck with the chase, mate.
I'm pretty sure that Mark (as in Mark and Sam) loads all his own ammunition, (although I am happy to be corrected if I've got that wrong) which, unfortunately isn't an option for me, I would only be using factory. Whilst I know a mile is possible for the Creedmoor, the general consensus seems to be that past 1000 (with factory) the bigger, high BC 225s from the 300PRC match, would be a better bet.
The difference in the factory ammo (aside from the Creedmoor having better availability) seems to be that the 6.5 is ball park £30 to £35 for a box of 20, where as the PRC is £50 for 20, so there's no getting away from the fact that the 6.5 has the 300 licked in that department. But given the amount of shooting that I would do (the mile wouldn't be the only discipline that I dabble in) that extra cost is just inside what I would accept for a long gun ammo costs.
Also, if I am totally honest with myself, I prefer a thumper.
In terms of build costs for a rifle with the same specs, I don't know what the difference in cost would be going from a 6.5 to a long action 30? That's something I'd have to run past Baldie?
Thanks again fellas