UM550,
N540 is good stuff. I haven't used it in any of my 308s, but I do use it quite heavily in my 5.56mm Match ammo for XC-HP competition. Primarily for heavy weight bullets such as the 77 and 82s, but I think it'd be just a bit too slow for anything much lighter than the 69s. By extension, it should be ideal for the 308s with bullets of 175 grains or above, since there's a lot of overlap between these applications. Should be an excellent choice for you!
Dave300,
Not this year, though it's still getting a lot of discussion and they are considering it. I'll be heading off to the SHOT show in a few weeks, and I'm sure we'll be chatting it up some more then. Couple months after that I'll be headed to Germany for the IWA show, which will give them a bit more time to kick it around a bit. Anyway, I'm sure we'll restart the conversation again in Nuremburg, so who knows? I'm pushing for it, but am a rather small cog in a very, very large machine. More than happy to keep you posted if I hear anything more, though.