Welcome to the forum, If you do a search, you should find alot of information here on this round, there is also a very good article on the 6mmBR forum, here's the link:
As your username is familiar on other UK sites, so you might be aware I have a similar set up with a .291" nk.
Current deer load is 49g of H4350 under a 140 SST gives me 2870fps.
For target work I use 48.5g of H3831SC under a 142 SMK giving me 2670fps - a bit slow, but using any more powder (half a grain) starts showing serious pressure. I intend to try 4350 or Vit 160 as an alternative to 4831SC, but have yet to find the time for load development.
You should like this round, it really is easy to load, damn accurate and has the legs to enable you to reach out to extended range deer with relative ease. (providing you have rangefinder, ballistics table and can read the wind) [img]/ubbthreads/images/graemlins/wink.gif[/img]