This is spot on...Any custom rifle that won't shoot .5 in whatever cartridge isn't worthy of the name. The good ones easily hit .2-.3 and that is my expectation of a custom. There is no such thing as an inherently inaccurate round but some rounds like the 338 WM and 338 RUM do seem to be easier to tune for some reason.
Not done yet. It is a very specialised build so don't expect to see it for another couple of months. How did they manage to build up the bolt face enough to offset that big a difference and what kind of action did you build the RUM on?Dean2 how is your 338-378 build going I am on AO. Had I known what I know now I would have gone 338-378 as well. Turned out my bolt face is .580 not .534. I can't complain my RUM is shooting ral well.